Review TRENDS in Biotechnology Vol.25 No.3 Full text provided by ww. ScienceDirect ELSEVIER Industrial biotechnology for the production of bio-based chemicals a cradle-to-grave perspective Rajni Hatti-Kaul,Ulrika Tornvall,Linda Gustafsson2 and Pal Borjesson2 1 Department of Biotechnology,Centre for Chemistry Chemical Engineering,Lund University,Box 124,SE-221 00 Lund,Sweden 2Environmental and Energy Systems Studies,Department of Technology and Society,Lund University,Box 118,SE-221 00 Lund, Sweden Shifting the resource base for chemical production from that integrates social,safety,health and environmental fossil feedstocks to renewable raw materials provides benefits with the technological and economic objectives of exciting possibilities for the use of industrial biotechnol- its activities. ogy-based process tools.This review gives an indication The concept of 'green chemistry'was introduced in the of the current developments in the transition to bio- early 1990s by the US Environmental Protection Agency based production,with a focus on the production of (http://www.epa.gov/),in order 'to promote chemical tech- chemicals,and points out some of the challenges that nologies that reduce or eliminate the use or generation of exist in the large-scale implementation of industrial hazardous substances in the design,manufacture and use biotechnology.Furthermore,the importance of evaluat- of chemical products'.Its guiding rule is prevention rather ing the environmental impact of bio-based products than cure.Green chemistry is currently associated with the with respect to their entire life cycle is highlighted, 12 principles formulated by Paul Anastas and John War- demonstrating that the choice of the raw material often ner [2],which advocate a decrease in the environmental turns out to be an important parameter influencing the impact of a chemical product by considering aspects of its life cycle performance. entire life cycle-from raw material to product use and fate. Examples of these are using renewable feedstocks,selec- Introduction tive catalysts and alternative,non-toxic solvents;high Chemistry has had,and continues to have,a fundamental atom efficiency;minimizing risks,waste generation and role in almost every aspect of modern society.Despite energy consumption;and design of safer and biodegradable providing us with a vast array of useful products,the chemicals.These principles have since been supplemented chemical industry has been subjected to close scrutiny by the 12 principles of green engineering,which provide a owing to concerns about its reliance on fossil resources, structure to create and assess the elements of design its environmentally damaging production processes,and relevant to maximizing sustainability [3]. the production of toxic by-products,waste and products In view of the above,this review highlights the current that are not readily recyclable or degradable after their trend towards the bio-based production of chemicals and useful life.The industry has come under increasing pres- the potential of industrial biotechnology to provide the sure to make chemical production more eco-friendly.Gov- process tools to achieve this.Furthermore,it stresses ernments across the globe are increasing the fines levied the need for evaluation of the environmental impact of for pollution,the costs of waste disposal,and penal taxa- the products from a life cycle perspective.We have chosen tion for the storage of large quantities of dangerous chemi- to mention only briefly the production of biofuels because cals.In the EU,new chemical legislations are being this is already extensively dealt with in several reports; introduced,to improve the levels of protection of human however,it should be understood that the two sectors are health and the environment from chemical risks.For closely related and can also be synergistic. example,the recently proposed REACH (registration, evaluation and authorization of chemicals;http://ec. A shift from fossil to bio-based raw material europa.eu/environment/chemicals/reach/reach_intro.htm) Currently,the products made from bio-based raw regulatory framework demands registration and safety materials represent only a minor fraction of the output testing of all produced or imported chemicals.A more of the chemical industry.The efforts to shift the prime product-or sector-related legislation,such as the Restric- resource base of the industry from non-renewable to tion on Hazardous Substances (RoHS)[1],prohibits or renewable feedstocks have recently gained momentum, severely restricts the use of most dangerous chemicals in primarily because of the rapid rise in the costs of mineral electronic and electrical equipment.The sustainability of oil and an increasing concern about the depletion of these the chemical industry thus calls for a business strategy resources in the near future.The world production of plant Corresponding author:Hatti-Kaul,R.(rajni.hatti-kaul@biotek.lu.se). biomass is vast and is more than enough to match the Available online 17 January 2007. demand for the co-production of chemicals,materials and www.sciencedirect.com 0167-7799/$-see front matter 2006 Elsevier Ltd.All rights reserved.doi:10.1016/j.tibtech.2007.01.001
Industrial biotechnology for the production of bio-based chemicals – a cradle-to-grave perspective Rajni Hatti-Kaul1 , Ulrika To¨ rnvall1 , Linda Gustafsson2 and Pa˚l Bo¨ rjesson2 1 Department of Biotechnology, Centre for Chemistry & Chemical Engineering, Lund University, Box 124, SE-221 00 Lund, Sweden 2 Environmental and Energy Systems Studies, Department of Technology and Society, Lund University, Box 118, SE-221 00 Lund, Sweden Shifting the resource base for chemical production from fossil feedstocks to renewable raw materials provides exciting possibilities for the use of industrial biotechnology-based process tools. This review gives an indication of the current developments in the transition to biobased production, with a focus on the production of chemicals, and points out some of the challenges that exist in the large-scale implementation of industrial biotechnology. Furthermore, the importance of evaluating the environmental impact of bio-based products with respect to their entire life cycle is highlighted, demonstrating that the choice of the raw material often turns out to be an important parameter influencing the life cycle performance. Introduction Chemistry has had, and continues to have, a fundamental role in almost every aspect of modern society. Despite providing us with a vast array of useful products, the chemical industry has been subjected to close scrutiny owing to concerns about its reliance on fossil resources, its environmentally damaging production processes, and the production of toxic by-products, waste and products that are not readily recyclable or degradable after their useful life. The industry has come under increasing pressure to make chemical production more eco-friendly. Governments across the globe are increasing the fines levied for pollution, the costs of waste disposal, and penal taxation for the storage of large quantities of dangerous chemicals. In the EU, new chemical legislations are being introduced, to improve the levels of protection of human health and the environment from chemical risks. For example, the recently proposed REACH (registration, evaluation and authorization of chemicals; http://ec. europa.eu/environment/chemicals/reach/reach_intro.htm) regulatory framework demands registration and safety testing of all produced or imported chemicals. A more product- or sector-related legislation, such as the Restriction on Hazardous Substances (RoHS) [1], prohibits or severely restricts the use of most dangerous chemicals in electronic and electrical equipment. The sustainability of the chemical industry thus calls for a business strategy that integrates social, safety, health and environmental benefits with the technological and economic objectives of its activities. The concept of ‘green chemistry’ was introduced in the early 1990s by the US Environmental Protection Agency (http://www.epa.gov/), in order ‘to promote chemical technologies that reduce or eliminate the use or generation of hazardous substances in the design, manufacture and use of chemical products’. Its guiding rule is prevention rather than cure. Green chemistry is currently associated with the 12 principles formulated by Paul Anastas and John Warner [2], which advocate a decrease in the environmental impact of a chemical product by considering aspects of its entire life cycle – from raw material to product use and fate. Examples of these are using renewable feedstocks, selective catalysts and alternative, non-toxic solvents; high atom efficiency; minimizing risks, waste generation and energy consumption; and design of safer and biodegradable chemicals. These principles have since been supplemented by the 12 principles of green engineering, which provide a structure to create and assess the elements of design relevant to maximizing sustainability [3]. In view of the above, this review highlights the current trend towards the bio-based production of chemicals and the potential of industrial biotechnology to provide the process tools to achieve this. Furthermore, it stresses the need for evaluation of the environmental impact of the products from a life cycle perspective. We have chosen to mention only briefly the production of biofuels because this is already extensively dealt with in several reports; however, it should be understood that the two sectors are closely related and can also be synergistic. A shift from fossil to bio-based raw material Currently, the products made from bio-based raw materials represent only a minor fraction of the output of the chemical industry. The efforts to shift the prime resource base of the industry from non-renewable to renewable feedstocks have recently gained momentum, primarily because of the rapid rise in the costs of mineral oil and an increasing concern about the depletion of these resources in the near future. The world production of plant biomass is vast and is more than enough to match the demand for the co-production of chemicals, materials and Review TRENDS in Biotechnology Vol.25 No.3 Corresponding author: Hatti-Kaul, R. (rajni.hatti-kaul@biotek.lu.se). Available online 17 January 2007. www.sciencedirect.com 0167-7799/$ – see front matter 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.tibtech.2007.01.001
120 Review TRENDS in Biotechnology Vol.25 No.3 fuels with the demand of foods and feeds[4].Optimal use of agricultural productivity,agricultural and forest residues, waste biomass,and currently non-used land should enable the further expansion of the bio-based industry,provided the technological and economic limitations are overcome. The growing of dedicated crops for non-food production and breeding,to increase the yield performance of useful Photosynthesis Extraction plants,is already practised on large scale [5].Furthermore. the ability to alter the composition of the raw material, either by traditional breeding methods or by molecular biology,has no parallel in petroleum refining C02+H20 A change in the feedstock from hydrocarbons to biological molecules will,of course,radically alter the technological basis of the industry.Primarily,there is a need for technologies that enable the economical proces- Biodegradation Biotechnology sing of complex biomass,particularly crop residues and wastes-the production of bioethanol from lignocellulose is one example.Here,the main barrier is the hydrolysis ofthe cellulose to sugar,which is traditionally accomplished by acid hydrolysis;however,enzymatic hydrolysis provides TRENDS in Biotechnology advantages,including increased yield [6].Iogen,a Cana- Figure 1.A closed cycle of production of biodegradable chemicals from renewable dian biotech company (http://www.iogen.ca/),has been feedstocks using industrial biotechnology.The products containing such running an experimental plant since 2004 that uses the chemicals are environmentally benign in comparison with the products made from fossil feedstocks using end-of-pipe technologies(i.e.those that lead to non- enzymatic hydrolysis of lignocellulose,in a process free of biodegradable products and wastes).The bio-based chemicals can be biodegraded fossil fuel.Although the available cellulose raw material is into carbon dioxide and water,which are used during photosynthesis for the estimated to be enough to replace 40%of the gasoline used production of plant biomass.An example of an oleochemical product made using industrial biotechnology for an application in paints is shown. in the US,the costs still need to be reduced (e.g.by improving enzyme efficiency through genetic engineering) The availability of inexpensive bioethanol should sub Figure 1.Industrial biotechnology,also known as 'white sequently promote its use as a precursor for other organic biotechnology'in Europe,relies on the use of whole cells or molecules in the chemical industry.For example,ethylene enzymes as catalysts,and such processes are already used -which forms the backbone of several products,including for the manufacture of several commodity and speciality ethanol,in the petrochemical industry-could be made, chemicals 8].Biocatalysis has more commonly been instead.by dehydration of ethanol manufactured by the directed towards the production of high-value products for fermentation of carbohydrate feedstock [4].Hence,direct- the fine chemicals and pharmaceutical industries [9-11]; ing innovation and technological development from the according to a recent survey,22 out of 38 large-scale asym- perspective of a sustainable bio-based society remains a metric syntheses already incorporate biocatalysis [121.The major challenge for the chemical industry.A good starting production of chemicals using industrial biotechnology is point is to link the production of chemicals with the rapidly often able to meet several of the green chemistry principles, emerging bio-energy industries,from which important bio- particularly reduced energy consumption and waste gener- platform molecules,including glycerol(from a by-product ation,selective catalysis,and biodegradable products. in biodiesel production),bioethanol and biobutanol Furthermore,it can replace multi-step chemical synthesis (through new process developed by BP-DuPont [www2. with a single step involving low energy and less material dupont.com/Biofuels/en_US/]),will become available. input [13],and even enables the synthesis of products that In moving towards the realization of a bio-based are not possible chemically.Organic synthesis using bioca- production,the concept of a biorefinery,analogous to the talysis has been possible by performing reactions in pre- petroleum refinery,has emerged,where the processing dominantly water-free media,or in water-organic biphasic facilities based on different technologies are centred on systems [10,14,15].Owing to concerns regarding volatile an agricultural (or forest)base,and the biomass is con- organic carbon emissions,there is a development towards verted into various biochemical and chemical intermedi- replacing the organic solvents used as reaction media with ates that are fed into a variety of downstream product lines alternatives such as supercritical carbon dioxide and ionic [7].By producing multiple products,a biorefinery can take liquids [16,17]or,preferably,solvent-free media. advantage of the natural complexity and differences in Recent advances in genomics,proteomics and biomass components and intermediates and,hence,maxi- bioinformatics provide access to an enormous information mize the value derived from the biomass. base for facilitating the choice of suitable microorganisms and enzymes for bioconversions.Engineering of metabolic Industrial biotechnology-linking green chemistry and pathways in microorganisms enables the production of bio-based production many of the platform chemicals used in the industry,for Biotechnology has attracted a great deal of attention as a example,1,3-propanediol,succinic acid and butanol [18]. potentially important tool in facilitating the paradigm shift New biocatalysts are being discovered by studying novel from fossil to bio-based production,as illustrated in microorganisms isolated from,for example,extreme www.sciencedirect.com
fuels with the demand of foods and feeds [4]. Optimal use of agricultural productivity, agricultural and forest residues, waste biomass, and currently non-used land should enable the further expansion of the bio-based industry, provided the technological and economic limitations are overcome. The growing of dedicated crops for non-food production and breeding, to increase the yield performance of useful plants, is already practised on large scale [5]. Furthermore, the ability to alter the composition of the raw material, either by traditional breeding methods or by molecular biology, has no parallel in petroleum refining. A change in the feedstock from hydrocarbons to biological molecules will, of course, radically alter the technological basis of the industry. Primarily, there is a need for technologies that enable the economical processing of complex biomass, particularly crop residues and wastes – the production of bioethanol from lignocellulose is one example. Here, the main barrier is the hydrolysis of the cellulose to sugar, which is traditionally accomplished by acid hydrolysis; however, enzymatic hydrolysis provides advantages, including increased yield [6]. Iogen, a Canadian biotech company (http://www.iogen.ca/), has been running an experimental plant since 2004 that uses the enzymatic hydrolysis of lignocellulose, in a process free of fossil fuel. Although the available cellulose raw material is estimated to be enough to replace 40% of the gasoline used in the US, the costs still need to be reduced (e.g. by improving enzyme efficiency through genetic engineering). The availability of inexpensive bioethanol should subsequently promote its use as a precursor for other organic molecules in the chemical industry. For example, ethylene – which forms the backbone of several products, including ethanol, in the petrochemical industry – could be made, instead, by dehydration of ethanol manufactured by the fermentation of carbohydrate feedstock [4]. Hence, directing innovation and technological development from the perspective of a sustainable bio-based society remains a major challenge for the chemical industry. A good starting point is to link the production of chemicals with the rapidly emerging bio-energy industries, from which important bioplatform molecules, including glycerol (from a by-product in biodiesel production), bioethanol and biobutanol (through new process developed by BP–DuPont [www2. dupont.com/Biofuels/en_US/]), will become available. In moving towards the realization of a bio-based production, the concept of a biorefinery, analogous to the petroleum refinery, has emerged, where the processing facilities based on different technologies are centred on an agricultural (or forest) base, and the biomass is converted into various biochemical and chemical intermediates that are fed into a variety of downstream product lines [7]. By producing multiple products, a biorefinery can take advantage of the natural complexity and differences in biomass components and intermediates and, hence, maximize the value derived from the biomass. Industrial biotechnology – linking green chemistry and bio-based production Biotechnology has attracted a great deal of attention as a potentially important tool in facilitating the paradigm shift from fossil to bio-based production, as illustrated in Figure 1. Industrial biotechnology, also known as ‘white biotechnology’ in Europe, relies on the use of whole cells or enzymes as catalysts, and such processes are already used for the manufacture of several commodity and speciality chemicals [8]. Biocatalysis has more commonly been directed towards the production of high-value products for the fine chemicals and pharmaceutical industries [9–11]; according to a recent survey, 22 out of 38 large-scale asymmetric syntheses already incorporate biocatalysis [12]. The production of chemicals using industrial biotechnology is often able to meet several of the green chemistry principles, particularly reduced energy consumption and waste generation, selective catalysis, and biodegradable products. Furthermore, it can replace multi-step chemical synthesis with a single step involving low energy and less material input [13], and even enables the synthesis of products that are not possible chemically. Organic synthesis using biocatalysis has been possible by performing reactions in predominantly water-free media, or in water–organic biphasic systems [10,14,15]. Owing to concerns regarding volatile organic carbon emissions, there is a development towards replacing the organic solvents used as reaction media with alternatives such as supercritical carbon dioxide and ionic liquids [16,17] or, preferably, solvent-free media. Recent advances in genomics, proteomics and bioinformatics provide access to an enormous information base for facilitating the choice of suitable microorganisms and enzymes for bioconversions. Engineering of metabolic pathways in microorganisms enables the production of many of the platform chemicals used in the industry, for example, 1,3-propanediol, succinic acid and butanol [18]. New biocatalysts are being discovered by studying novel microorganisms isolated from, for example, extreme Figure 1. A closed cycle of production of biodegradable chemicals from renewable feedstocks using industrial biotechnology. The products containing such chemicals are environmentally benign in comparison with the products made from fossil feedstocks using end-of-pipe technologies (i.e. those that lead to nonbiodegradable products and wastes). The bio-based chemicals can be biodegraded into carbon dioxide and water, which are used during photosynthesis for the production of plant biomass. An example of an oleochemical product made using industrial biotechnology for an application in paints is shown. 120 Review TRENDS in Biotechnology Vol.25 No.3 www.sciencedirect.com
Review TRENDS in Biotechnology Vol.25 No.3 121 environments [19]and also by using metagenomics [20]. most cases these benefits have not been comparatively Evolution of these enzymes to suit a particular process has weighted against the overall inventory of materials and further been possible in vitro,at substantially higher rates energy required to generate a given product.Hence,when than achieved in nature [21.221.Furthermore,the devel- switching from fossil feedstocks and chemical production opment of both high-expression production organisms and processes to renewable feedstocks processed with biotech- suitable cultivation strategies for enzyme production has nological methods the assessment of the environmental shown potential for their availability at reduced costs.The and economic benefits provided by the process should cover advances made by Genencor (http://www.genencor.com/) the entire life cycle (cradle-to-grave)of a product-raw and Novozymes (http://www.novozymes.com/en)in redu- material production,manufacture,product use and fate cing cellulase production costs and improving performance [27].The major elements of the environmental assessment provide good examples for the use of biotechnology to include primary energy use,raw materials use,emissions improve biocatalysis for biomass hydrolysis,which could to all media,toxicity,safety risk and land use [28).The be an important enabler for the bio-based products indus- significance and relative importance of the different factors try (Box 1)[23]. with respect to the environmental impact has been The chemical industry in Europe,which contributes assessed [29]using a method that is usually referred to ~28%of the demand for chemicals in the world,has ident- as a life cycle assessment(LCA). ified industrial biotechnology as a key emerging technology First developed ~30 years ago,the LCA is now a area(http//www.suschem.org/)[24].The share of biotech- valuable tool in the chemical industry [28,30].It is used nological processes in the production of various chemical to compare and benchmark the performance of a product products is expected to rise from the current level of~5%to against several competing,alternative processes and pro- 20%by 2010.The greatest impact will be on the fine chemi- ducts,and to find hot spots in the life cycle that might cals sector,where up to 60%of the products might be based require performance improvements.Figure 2 shows the on biotechnology within this time frame [13.251. different improvements that can be made at different In a bio-based production,industrial biotechnology also stages in the life cycle from a green chemistry perspective. interfaces with plant biotechnology(green biotechnology), LCAs are also used in industry for strategic planning and where gene technology is applied to accelerate the process marketing purposes [28,30];many eco-labels and environ- of plant breeding for crop improvement or for altering the mental product declarations(EPD)are based on LCAs.In composition of the feedstock for a desired product.For the eco-efficiency analysis used by BASF,equal weight is example,efforts are made to meet the demands for tai- given to the LCA as to the costs of the product,which lor-made oils and fats by increasing the content of indi- include the costs during the production,the usage,and for vidual fatty acids or the introduction of a new fatty acid the disposal or recycling of the spent product [28]. High oleic'soybean and high lauric acid'rapeseed have Compared with the number of LCA studies of been developed already by genetic engineering [261. conventional chemical processes and products,the number of LCA studies that evaluate bioprocesses and bio-based A cradle-to-grave perspective for sustainable chemicals with respect to environmental and economical production benefits is rather limited [30.311.even if the need has been Although industrial biotechnology is intuitively associated increasing recently.The few studies reported so far have with cleaner chemistry and cleaner industrial processes,in shown that the principle of using renewable feedstock is not necessarily favourable in all situations and for all environmental aspects[31].By its nature,the use ofrenew- Box 1.Challenges that lie ahead for industrial able raw materials gives rise to several specific problems, biotechnology in bio-based production such as the use of a dedicated crop for manufacture-where Industrial biotechnology is a multidisciplinary technology based on the various potential feedstock crops have their own microbial,plant or animal cells,or their components or enzymes,as specific characteristics and different environmental per- catalysts.It includes the integrated application of disciplines such as formances.For example,the environmental impact of biochemistry,microbiology,molecular genetics and process tech- nology to develop useful processes and products.Several techno- annual feedstock crops using large amounts of chemical logical and implementation barriers need to be overcome before its fertilisers and pesticides is normally much higher than the full potential can be realized in the chemical industry. impact of perennial crops or annual crops using limited Development of novel and improved biocatalysts for the proces- amounts of agrochemicals.The choice of feedstock crop and sing of biomass and production of chemicals. cultivation system will also affect the long-term soil ferti- Development of effective tools and techniques for rapid screening of biocatalysts with desired functions and properties lity and biodiversity [32]. Cost-effective production of biocatalysts by developing efficient The need to include the viewpoint of competing land-use high-expression hosts and suitable cultivation technology. options in the LCAs of green chemicals has been high- Improving technologies for bioprocesses (e.g.multiphase reac- lighted [33].For example,a competing land-use option to tors and solvent-free reactions)and subsequent product recovery. the cultivation of crops for chemical production might be Integration of biotechnology with chemical processes. Quantifying and valuing the real environmental and economic the cultivation of dedicated energy crops for replacing fossil benefits of the processes fuels,which,potentially,could be a more efficient way to The demonstration of case studies. reduce the emissions of greenhouse gases.A careful Communication with the important stakeholders,including pro- approach,including comprehensive analyses of the various ducers of renewable feedstock and producers and users of the biomass feedstock options and alternative usage opportu- affected chemicals. nities,should be applied,to find the best options for green www.sciencedirect.com
environments [19] and also by using metagenomics [20]. Evolution of these enzymes to suit a particular process has further been possible in vitro, at substantially higher rates than achieved in nature [21,22]. Furthermore, the development of both high-expression production organisms and suitable cultivation strategies for enzyme production has shown potential for their availability at reduced costs. The advances made by Genencor (http://www.genencor.com/) and Novozymes (http://www.novozymes.com/en) in reducing cellulase production costs and improving performance provide good examples for the use of biotechnology to improve biocatalysis for biomass hydrolysis, which could be an important enabler for the bio-based products industry (Box 1) [23]. The chemical industry in Europe, which contributes 28% of the demand for chemicals in the world, has identified industrial biotechnology as a key emerging technology area (http://www.suschem.org/) [24]. The share of biotechnological processes in the production of various chemical products is expected to rise from the current level of 5% to 20% by 2010. The greatest impact will be on the fine chemicals sector, where up to 60% of the products might be based on biotechnology within this time frame [13,25]. In a bio-based production, industrial biotechnology also interfaces with plant biotechnology (green biotechnology), where gene technology is applied to accelerate the process of plant breeding for crop improvement or for altering the composition of the feedstock for a desired product. For example, efforts are made to meet the demands for tailor-made oils and fats by increasing the content of individual fatty acids or the introduction of a new fatty acid. ‘High oleic’ soybean and ‘high lauric acid’ rapeseed have been developed already by genetic engineering [26]. A cradle-to-grave perspective for sustainable production Although industrial biotechnology is intuitively associated with cleaner chemistry and cleaner industrial processes, in most cases these benefits have not been comparatively weighted against the overall inventory of materials and energy required to generate a given product. Hence, when switching from fossil feedstocks and chemical production processes to renewable feedstocks processed with biotechnological methods the assessment of the environmental and economic benefits provided by the process should cover the entire life cycle (cradle-to-grave) of a product – raw material production, manufacture, product use and fate [27]. The major elements of the environmental assessment include primary energy use, raw materials use, emissions to all media, toxicity, safety risk and land use [28]. The significance and relative importance of the different factors with respect to the environmental impact has been assessed [29] using a method that is usually referred to as a life cycle assessment (LCA). First developed 30 years ago, the LCA is now a valuable tool in the chemical industry [28,30]. It is used to compare and benchmark the performance of a product against several competing, alternative processes and products, and to find hot spots in the life cycle that might require performance improvements. Figure 2 shows the different improvements that can be made at different stages in the life cycle from a green chemistry perspective. LCAs are also used in industry for strategic planning and marketing purposes [28,30]; many eco-labels and environmental product declarations (EPD) are based on LCAs. In the eco-efficiency analysis used by BASF, equal weight is given to the LCA as to the costs of the product, which include the costs during the production, the usage, and for the disposal or recycling of the spent product [28]. Compared with the number of LCA studies of conventional chemical processes and products, the number of LCA studies that evaluate bioprocesses and bio-based chemicals with respect to environmental and economical benefits is rather limited [30,31], even if the need has been increasing recently. The few studies reported so far have shown that the principle of using renewable feedstock is not necessarily favourable in all situations and for all environmental aspects [31]. By its nature, the use of renewable raw materials gives rise to several specific problems, such as the use of a dedicated crop for manufacture – where the various potential feedstock crops have their own specific characteristics and different environmental performances. For example, the environmental impact of annual feedstock crops using large amounts of chemical fertilisers and pesticides is normally much higher than the impact of perennial crops or annual crops using limited amounts of agrochemicals. The choice of feedstock crop and cultivation system will also affect the long-term soil fertility and biodiversity [32]. The need to include the viewpoint of competing land-use options in the LCAs of green chemicals has been highlighted [33]. For example, a competing land-use option to the cultivation of crops for chemical production might be the cultivation of dedicated energy crops for replacing fossil fuels, which, potentially, could be a more efficient way to reduce the emissions of greenhouse gases. A careful approach, including comprehensive analyses of the various biomass feedstock options and alternative usage opportunities, should be applied, to find the best options for green Box 1. Challenges that lie ahead for industrial biotechnology in bio-based production Industrial biotechnology is a multidisciplinary technology based on microbial, plant or animal cells, or their components or enzymes, as catalysts. It includes the integrated application of disciplines such as biochemistry, microbiology, molecular genetics and process technology to develop useful processes and products. Several technological and implementation barriers need to be overcome before its full potential can be realized in the chemical industry. Development of novel and improved biocatalysts for the processing of biomass and production of chemicals. Development of effective tools and techniques for rapid screening of biocatalysts with desired functions and properties. Cost-effective production of biocatalysts by developing efficient high-expression hosts and suitable cultivation technology. Improving technologies for bioprocesses (e.g. multiphase reactors and solvent-free reactions) and subsequent product recovery. Integration of biotechnology with chemical processes. Quantifying and valuing the real environmental and economic benefits of the processes. The demonstration of case studies. Communication with the important stakeholders, including producers of renewable feedstock and producers and users of the affected chemicals. Review TRENDS in Biotechnology Vol.25 No.3 121 www.sciencedirect.com
122 Review TRENDS in Biotechnology Vol.25 No.3 Biocatalysis Waste optimization minimization Pre-manufacturing Low energy Renewable input feedstocks Solvent Biocatalysts substitution Manufacturing Energy Alternative efficient routes Efficient Product delivery Degradable or transportation recyclable packaging Environmentally Safer and non- benign chemicals Product use toxic chemicals Recyclable Biodegradable products End-of-life chemicals TRENDS in Biotechnology Figure 2.Green chemistry and industrial biotechnology applied from cradle-to-grave. chemicals from renewable feedstock.Examples of a few energy source or,even better,by using wind power as the bio-based products from a life cycle perspective are pro- energy source [30].The process also gains a substantial vided below. energy advantage if waste biomass is used as a feedstock [35].Incineration or composting was suggested as a Bioplastics from corn preferred option to landfill deposition for the waste A substantial fraction of the raw materials in the chemical management of the polymers made from renewable feed- industry is converted to polymers.Biodegradable polymers stocks [36]. based on renewable raw materials have attracted consider- able attention for replacing at least some of the traditional Oleochemical products for wood coatings plastics [34].Among these are polyhydroxyalkanoate Oleochemicals are hydrocarbons that are derived from (PHA)-a microbially synthesized polyester manufactured vegetable oils;they are closely related to petrochemicals by Metabolix(http://www.metabolix.com)-and polylactic and are well suited for the transformations that are under- acid (PLA,NatureWorksTM),a product of Cargill Dow stood by the chemical industry.Microbial and enzymatic (http://www.natureworksllc.com)from lactic acid gener- transformations can be used for the production of several ated by fermentation.The LCA for the production of oleochemical products [26].As part of Greenchem,a PHA using corn as a feedstock showed no environmental research programme at Lund University in Sweden,bio- benefits because the amount of fossil fuel used to produce catalytic and other 'green'processes are being evaluated 1kg of PHA exceeds that required to produce an equal for the production of coating,lubricant and surfactant amount of the polystyrene it would replace [31]. products from oleochemicals (Figure 3).An assessment The main hot spots in the life cycle of bioplastics with of the total energy consumption for wax ester production respect to energy input were the raw material production by lipase-catalysed esterification demonstrated that 34% and the fermentation process,particularly in the case of less energy was consumed and less waste generated than PHA.Corn is one of the more energy-intensive crops and by chemical esterification,where a strong acid is used as accounts for substantial amounts of fertilizer.insecticide catalyst [37].However,from a life-cycle perspective,com- and herbicide use.The subsequent transport and proces- parison of the wax ester as a wood-coating ingredient with sing of the corn,involving wet milling and fractionation other coating products showed that UV-curable coatings to yield gluten meal,oil,starch and sugar,also expend based on fossil feedstock were the most favourable alterna energy.For such a feedstock,the fuel source used for tive in all environmental categories [38).A similar obser- energy generation could have a profound impact on the vation was made using the eco-efficiency analysis method environmental credentials of the product.If the overall of BASF [281. energy demand was satisfied,for the large part,from Most of the radiation-curable systems currently used non-fossil sources,products made from renewable are based on acrylates (39].Epoxidized vegetable oils have resources could possess a substantially better energy found an application in cation-curable coatings prepared balance compared with petrochemical polymers.Vink by exposure to UV radiation [401.Oils with a high oxirane et al.have estimated that a substantial reduction in content (e.g.linseed oil)are preferred for coating appli- the gross fossil energy use and greenhouse-gas emissions cations,owing to the possibility of a high degree of epox- can be achieved during PLA production if the lignin idation and,hence,extensive cross-linking [41].A fraction of the biomass feedstock is used as a thermal comparison of the LCAs for coatings based on acrylates www.sciencedirect.com
chemicals from renewable feedstock. Examples of a few bio-based products from a life cycle perspective are provided below. Bioplastics from corn A substantial fraction of the raw materials in the chemical industry is converted to polymers. Biodegradable polymers based on renewable raw materials have attracted considerable attention for replacing at least some of the traditional plastics [34]. Among these are polyhydroxyalkanoate (PHA) – a microbially synthesized polyester manufactured by Metabolix (http://www.metabolix.com) – and polylactic acid (PLA, NatureWorksTM), a product of Cargill Dow (http://www.natureworksllc.com) from lactic acid generated by fermentation. The LCA for the production of PHA using corn as a feedstock showed no environmental benefits because the amount of fossil fuel used to produce 1 kg of PHA exceeds that required to produce an equal amount of the polystyrene it would replace [31]. The main hot spots in the life cycle of bioplastics with respect to energy input were the raw material production and the fermentation process, particularly in the case of PHA. Corn is one of the more energy-intensive crops and accounts for substantial amounts of fertilizer, insecticide and herbicide use. The subsequent transport and processing of the corn, involving wet milling and fractionation to yield gluten meal, oil, starch and sugar, also expend energy. For such a feedstock, the fuel source used for energy generation could have a profound impact on the environmental credentials of the product. If the overall energy demand was satisfied, for the large part, from non-fossil sources, products made from renewable resources could possess a substantially better energy balance compared with petrochemical polymers. Vink et al. have estimated that a substantial reduction in the gross fossil energy use and greenhouse-gas emissions can be achieved during PLA production if the lignin fraction of the biomass feedstock is used as a thermal energy source or, even better, by using wind power as the energy source [30]. The process also gains a substantial energy advantage if waste biomass is used as a feedstock [35]. Incineration or composting was suggested as a preferred option to landfill deposition for the waste management of the polymers made from renewable feedstocks [36]. Oleochemical products for wood coatings Oleochemicals are hydrocarbons that are derived from vegetable oils; they are closely related to petrochemicals and are well suited for the transformations that are understood by the chemical industry. Microbial and enzymatic transformations can be used for the production of several oleochemical products [26]. As part of Greenchem, a research programme at Lund University in Sweden, biocatalytic and other ‘green’ processes are being evaluated for the production of coating, lubricant and surfactant products from oleochemicals (Figure 3). An assessment of the total energy consumption for wax ester production by lipase-catalysed esterification demonstrated that 34% less energy was consumed and less waste generated than by chemical esterification, where a strong acid is used as catalyst [37]. However, from a life-cycle perspective, comparison of the wax ester as a wood-coating ingredient with other coating products showed that UV-curable coatings based on fossil feedstock were the most favourable alternative in all environmental categories [38]. A similar observation was made using the eco-efficiency analysis method of BASF [28]. Most of the radiation-curable systems currently used are based on acrylates [39]. Epoxidized vegetable oils have found an application in cation-curable coatings prepared by exposure to UV radiation [40]. Oils with a high oxirane content (e.g. linseed oil) are preferred for coating applications, owing to the possibility of a high degree of epoxidation and, hence, extensive cross-linking [41]. A comparison of the LCAs for coatings based on acrylates Figure 2. Green chemistry and industrial biotechnology applied from cradle-to-grave. 122 Review TRENDS in Biotechnology Vol.25 No.3 www.sciencedirect.com
Review TRENDS in Biotechnology Vol.25 No.3 123 Oil Crops Crops Vegetable oil Carbohydrates Fatty alcohol Fatty acid Epoxides Coatings Lubricants Plasticizers Polymers Alkyl glycosides Sugar esters Fatty amide Wax esters Biosurfactants Personal care Coatings Personal care Pharmaceuticals Cleaning agents TRENDS in Biotechnology Figure 3.A glimpse of the potential of biocatalysis in transforming oleochemicals into various specialty chemicals.A vast amount of useful products in areas as diverse as personal care,pharmaceuticals,coatings,plasticizers and lubricants can be produced from bio-based raw materials using industrial biotechnology.Solid lines indicate the flow of main components from raw material to the end product;black broken lines refer to lipase-mediated reactions;and grey broken lines refer to reactions catalyzed by glycosidases used for producing the oleochemicals. with those based on epoxidized vegetable oils showed an expression of the epoxidized product [50,51].There remain important ecological advantage for the latter [421. considerable challenges before the promise of the'designer There are potential alternative routes for the production oil crops'is translated into a large-scale commercial reality of epoxidized oils or fatty acids.The industrial process used [52].However,if successful,this approach would be attrac- today involves the Prileshajev epoxidation reaction,in tive,from a LCA perspective,for the production of epox- which a peracid is used for oxygen transfer to the double idized and other oils with novel functionality. bonds in the fatty acid chains [43].The peracid is usually formed in situ from hydrogen peroxide and acetic or formic Conclusion acid,using a strong mineral acid or ion-exchange resin as The chemical industry is facing its second paradigm shift catalyst.However,this process can also be performed in a since the start of the petrochemistry industry:this time milder and more selective way using a lipase as a catalyst from petrochemistry to bio-based production.The main [44].This chemo-enzymatic process has also been per- focus,so far,has been in developing the biofuel market, formed under solvent-free conditions,adding further which is,in effect,driven by various policy incentives at environmental benefits [45]and,in fact,addressing almost different levels,for example,the carbon dioxide emission all of the above-mentioned principles of green chemistry trading system induced by the kyoto protocol,policy objec- Furthermore,fewer coloured epoxidation products are tives concerning energy security,stimulation of renewable obtained using the enzymatic route,which is indicative transportation fuels at an EU level,and the carbon dioxide of the mild process conditions [46].The major limitation of tax on fossil fuels in Sweden.In the chemical industry, the process,however,is the low stability of the enzyme in the use of fossil-based raw materials is often exempted the presence of the peroxide [47].For an economical pro- from environmental taxes,leading to much weaker incen- cess,the lipase stability has to be improved,for example, tives for increasing the use of renewable feedstock.A by protein engineering.Another possibility would be to use crucial issue to be addressed would be the expansion of a mono-oxygenase that can catalyse epoxidation directly the existing policy instruments that favour the increased from molecular oxygen and hence circumvent the use of use of renewable carbon dioxide neutral feedstock in the hydrogen peroxide [48]. chemical sector. Yet another possibility for obtaining epoxidized oils is by The biorefinery concept offers numerous possibilities to direct extraction from plants.The oilseed crops Euphorbia integrate the production of bio-energy and chemicals.This lagascae,Vernonia galamensis and other Vernonia species will also provide substantially higher value-added possess vernolic acid,which has a natural epoxide content economic activities,besides promoting production in agri- of 60-78%[46,49].However,commercial production of culture and forestry.Development of innovative and sus- these seed oils is hampered by high production costs tainable process technologies will be needed for realizing due to low seed yield.Breeding programmes to develop the shift to bio-based production of chemicals.The use of more-productive plants has been attempted,with limited technologies that provide improved conversion efficiency- success so far.Genetic engineering to introduce the fatty from raw material to final product-will increase the acid biosynthetic machinery from the wild plants into a environmental benefits of bio-based products because high-yielding oil crop has also been attempted,with low the raw material production is the dominant step in www.sciencedirect.com
with those based on epoxidized vegetable oils showed an important ecological advantage for the latter [42]. There are potential alternative routes for the production of epoxidized oils or fatty acids. The industrial process used today involves the Prileshajev epoxidation reaction, in which a peracid is used for oxygen transfer to the double bonds in the fatty acid chains [43]. The peracid is usually formed in situ from hydrogen peroxide and acetic or formic acid, using a strong mineral acid or ion-exchange resin as catalyst. However, this process can also be performed in a milder and more selective way using a lipase as a catalyst [44]. This chemo–enzymatic process has also been performed under solvent-free conditions, adding further environmental benefits [45] and, in fact, addressing almost all of the above-mentioned principles of green chemistry. Furthermore, fewer coloured epoxidation products are obtained using the enzymatic route, which is indicative of the mild process conditions [46]. The major limitation of the process, however, is the low stability of the enzyme in the presence of the peroxide [47]. For an economical process, the lipase stability has to be improved, for example, by protein engineering. Another possibility would be to use a mono-oxygenase that can catalyse epoxidation directly from molecular oxygen and hence circumvent the use of hydrogen peroxide [48]. Yet another possibility for obtaining epoxidized oils is by direct extraction from plants. The oilseed crops Euphorbia lagascae, Vernonia galamensis and other Vernonia species possess vernolic acid, which has a natural epoxide content of 60–78% [46,49]. However, commercial production of these seed oils is hampered by high production costs due to low seed yield. Breeding programmes to develop more-productive plants has been attempted, with limited success so far. Genetic engineering to introduce the fatty acid biosynthetic machinery from the wild plants into a high-yielding oil crop has also been attempted, with low expression of the epoxidized product [50,51]. There remain considerable challenges before the promise of the ‘designer oil crops’ is translated into a large-scale commercial reality [52]. However, if successful, this approach would be attractive, from a LCA perspective, for the production of epoxidized and other oils with novel functionality. Conclusion The chemical industry is facing its second paradigm shift since the start of the petrochemistry industry: this time from petrochemistry to bio-based production. The main focus, so far, has been in developing the biofuel market, which is, in effect, driven by various policy incentives at different levels, for example, the carbon dioxide emission trading system induced by the Kyoto protocol, policy objectives concerning energy security, stimulation of renewable transportation fuels at an EU level, and the carbon dioxide tax on fossil fuels in Sweden. In the chemical industry, the use of fossil-based raw materials is often exempted from environmental taxes, leading to much weaker incentives for increasing the use of renewable feedstock. A crucial issue to be addressed would be the expansion of the existing policy instruments that favour the increased use of renewable carbon dioxide neutral feedstock in the chemical sector. The biorefinery concept offers numerous possibilities to integrate the production of bio-energy and chemicals. This will also provide substantially higher value-added economic activities, besides promoting production in agriculture and forestry. Development of innovative and sustainable process technologies will be needed for realizing the shift to bio-based production of chemicals. The use of technologies that provide improved conversion efficiency – from raw material to final product – will increase the environmental benefits of bio-based products because the raw material production is the dominant step in Figure 3. A glimpse of the potential of biocatalysis in transforming oleochemicals into various specialty chemicals. A vast amount of useful products in areas as diverse as personal care, pharmaceuticals, coatings, plasticizers and lubricants can be produced from bio-based raw materials using industrial biotechnology. Solid lines indicate the flow of main components from raw material to the end product; black broken lines refer to lipase-mediated reactions; and grey broken lines refer to reactions catalyzed by glycosidases used for producing the oleochemicals. Review TRENDS in Biotechnology Vol.25 No.3 123 www.sciencedirect.com
124 Review TRENDS in Biotechnology Vol.25 No.3 the life cycle of the product.Industrial biotechnology is 25 Bachmann.R.and Riese.J.(2005)Industry overview:from promise to already making definite inroads into the chemical industry profit.Industrial Biotechnology 1,9-15 as an enabling technology,and its role will continue to 26 Biermann,U.et al.(2000)New syntheses with oils and fats as renewable raw materials for the chemical industry.Angew.Chem. grow during the coming years.So,too,will the use of Int.Ed.39,2206-2224 environmental assessment tools in making the right 27 Clark,J.H.(2006)Green chemistry:today (and tomorrow).Green choices of the available feedstocks and alternative tech- Chem.8,17-21 nologies. 28 Shonnard,D.R.et al.(2003)Industrial applications using BASF eco- efficiency analysis:perspectives on green engineering principles. Environ.Sci.Technol.37,5340-5348 Acknowledgements 29 International Organization for Standardization (1998)Life Cycle The financial support from the Swedish Foundation for Strategic Assessment.ISO/TR 14041:1998,ISO Environmental Research (MISTRA)is gratefully acknowledged.The 30 Vink,E.T.H.et al.(2003)Applications of life cycle assessment to authors would like to thank Bo Mattiasson,Erik Andersson and Anna NatureWorks polylactide (PLA)production.Polym.Degrad.Stabil. Petersson for their valuable help during the preparation of the manuscript. 80,403-419 31 Gerngross.T.U.(1999)Can biotechnology move us toward a References sustainable society?Nat.Biotechnol.17,541-544 1 Directive 2002/95/EC ofthe European Parliament and the Council of27 32 Mattsson,B.et al.(2000)Agricultural land use in life cycle assessment January 2003 on the restriction of the use of certain hazardous (LCA):casestudiesofthree vegetableoilcrops..Clean.Prod.8,283-292 substances in electrical and electronic equipment.The Official 33 Dornburg,V.et al.(2004)Comparing the land requirements,energy Journal of the European Union L37,19-23 savings,and greenhouse gas emissions reduction of biobased polymers 2 Anastas,P.and Warner,J.(1998)Green Chemistry:Theory and and bioenergy.An analysis and system extension of life-cycle Practice,Oxford University Press assessment studies.J.Ind.Ecol.7.93-116 3 Anastas,P.T.and Zimmerman,J.B.(2003)Design through the twelve 34 Mecking,S.(2004)Nature or petrochemistry?-biologically degradable principles of green engineering.Environ.Sci.Technol.37,95A-101A materials.Angew.Chem.Int.Ed.43.1078-1085 4 Dale,B.E.(2003)'Greening'the chemical industry:research and 35 Sakai,K.et al.(2004)Making plastics from garbage:a novel process development priorities for biobased industrial products.Chem. for poly-L-lactate production from municipal food waste.J.Ind.Ecol.7, Technol.Biotechnol.78.1093-1103 63_74 5 Hill,K.(2000)Fats and oils as oleochemical raw materials.Pure Appl. 36 Heyde,M.(1998)Ecological considerations on the use and production Chem.72,1255-1264 of biosynthetic and synthetic biodegradable polymers.Polym.Degrad. 6 Galbe,M.and Zacchi,G.(2002)A review of the production of ethanol Stabil.59,3-6 from softwood.Appl.Microbiol.Biotechnol.59,618-628 37 Petersson,A.E.V.et al.(2005)Wax esters produced by solvent-free 7 Kamm,B.et al.(2006)Biorefineries -Industrial Processes and energy-efficient enzymatic synthesis and their applicability as wood Produets:Status Quo and Future Directions (Vols 1 and 2)Wiley-VCH coatings.Green Chem.7,837-843 8 Organisation for Economic Co-operation and Development (OECD) 38 Gustafsson,L.and Borjesson,P.(2006)Life cycle assessment in green (2001)The Application of Biotechnology to Industrial Sustainability, chemistry-a comparison of various wood surface coatings.Int.LCA OECD Publications (http://www1.oecd.org/publications/e-book/ DOI:10.1065/lca2006.11.280 (http://www.scientificjournals.com/si/lca/ 9301061e.pdfD onlineFirst) 9 Thomas,S.M.et al.(2002)Biocatalysis:applications and potentials for 39 Philips,M.(1991)Radiation Curing Systems,VCH the chemical industry.Trends Biotechnol.20,238-242 40 Crivello,J.V.and Narayan,R.(1992)Epoxidized triglycerides as 10 Schmid,A.et al.(2001)Industrial biocatalysis today and tomorrow. renewable monomers in photoinitiated cationic polymerization. Nature409,258-268 Chem.Mater.4,692-699 11 Breuer,M.et al.(2004)Industrial methods for the production of 41 Overeem,A.et al.(1999)Seed oils rich in linolenic acid as renewable optically active intermediates.Angew.Chem.Int.Ed.43,788-824 feedstock for environment-friendly crosslinkers in powder coatings 12 Blaser,H.U.and Schmidt,E.(2003)Asymmetrie Catalysis on Ind.Crops Prod.10,157-165 Industrial Scale,Wiley-VCH 42 Diehlmann,A.and Kreisel,G.(2000)Environmental audit for UV 13 Sijbesma,F.(2003)White Biotechnology:Gateway to a More curable lacquers based on linseed oil.Farbe und Lack 106,101-105 Sustainable Future,EuropaBio 43 Swern,D.(1947)Electronic interpretation of the reaction of olefins 14 Klibanov,A.M.(2001)Improving enzymes by using them in organic with organic peracids.J.Am.Chem.Soc.69,1692-1698 solvents.Nature 409,241-246 44 Warwel,S.and Klaas,M.R.(1995)Chemoenzymic epoxidation of 15 Koeller,K.M.and Wong,C-H.(2001)Enzymes for chemical synthesis. unsaturated carboxylic acids.J.Mol.Catal.B:Enzym.1,29-35 Nature409,232-240 45 Orellana-Coca,C.et al.(2005)Chemo-enzymatic epoxidation of oleic 16 Compton,D.L.and King,J.W.(2001)Lipase-catalyzed synthesis of acid and methyl oleate in solvent-free medium.Biocatal.Biotransfor. triolein-based sunscreens in supercritical CO2.J.Amer.Oil Chem.Soc. 23,431-437 78,43-47 46 Buisman,G.J.H.(1999)Biodegradable binders and cross-linking 17 van Rantwijk,F.et al.(2003)Biocatalytic transformations in ionic agents from renewable resources.Surf.Coat.Int.82,127-130 liquids.Trends Biotechnol.21,131-138 47 Tornvall,U.et al.(2007)Stability of immobilized Candida antarctica 18 Chotani,G.et al.(2000)The commercial production of chemicals using lipase B during chemo-enzymatic epoxidation of fatty acid.Enzyme pathway engineering.Biochim.Biophys.Acta Mol.Cell Res.1543,434- Microb.Tech.40,447-451 455 48 Ruettinger,R.T.and Fulco.A.J.(1981)Epoxidation of unsaturated 19 Madigan,M.T.and Marrs,B.L.(1997)Extremophiles.Sci.Am.276, fatty acids by a soluble cytochrome P450-dependent system from 82-87 Bacillus megaterium.J.Biol.Chem.256,5728-5734 20 Lorenz,P.et al.(2002)Screening for novel enzymes for biocatalytic 49 Derksen,J.T.P.et al.(1995)Paints and coatings from renewable processes:accessing the metagenome as a resource of novel functional resources.Ind.Crops Prod.3,225-236 sequence space.Curr.Opin.Biotechnol.13,572-577 50 Singh,S.et al.(2000)Inhibition of polyunsaturated fatty acid 21 Turner,N.J.(2003)Directed evolution of enzymes for applied accumulation in plants expressing a fatty acid epoxygenase. biocatalysis.Trends Biotechnol.21,474-478 Biochem.Soc.Trans.28.940-942 22 Zhao,H.et al.(2002)Directed evolution of enzymes and pathways for 51 Thomaeus,S.et al.(2001)Distribution of fatty acids in polar and industrial biocatalysis.Curr.Opin.Biotechnol.13,104-110 neutral lipids during seed development in Arabidopsis thaliana 23 Kerr,E.(2004)Broadened applicability of use for industrial enzymes genetically engineered to produce acetylenic,epoxy and hydroxy Genetic Engineering News 24,1 fatty acids.Plant Sci.161,997-1003 24 Lorenz,P.and Zinke,H.(2005)White biotechnology:differences in US 52 Murphy,D.J.(2002)Biotechnology and the improvement of oil crops: and EU approaches?Trends Biotechnol.23,570-574 genes,dreams and realities.Phytochem.Rev.1,67-77 www.sciencedirect.com
the life cycle of the product. Industrial biotechnology is already making definite inroads into the chemical industry as an enabling technology, and its role will continue to grow during the coming years. So, too, will the use of environmental assessment tools in making the right choices of the available feedstocks and alternative technologies. Acknowledgements The financial support from the Swedish Foundation for Strategic Environmental Research (MISTRA) is gratefully acknowledged. The authors would like to thank Bo Mattiasson, Erik Andersson and Anna Petersson for their valuable help during the preparation of the manuscript. References 1 Directive 2002/95/EC of the European Parliament and the Council of 27 January 2003 on the restriction of the use of certain hazardous substances in electrical and electronic equipment. The Official Journal of the European Union L37, 19–23 2 Anastas, P. and Warner, J. (1998) Green Chemistry: Theory and Practice, Oxford University Press 3 Anastas, P.T. and Zimmerman, J.B. (2003) Design through the twelve principles of green engineering. Environ. Sci. Technol. 37, 95A–101A 4 Dale, B.E. (2003) ‘Greening’ the chemical industry: research and development priorities for biobased industrial products. J. Chem. Technol. Biotechnol. 78, 1093–1103 5 Hill, K. (2000) Fats and oils as oleochemical raw materials. Pure Appl. Chem. 72, 1255–1264 6 Galbe, M. and Zacchi, G. (2002) A review of the production of ethanol from softwood. Appl. Microbiol. Biotechnol. 59, 618–628 7 Kamm, B. et al. (2006) Biorefineries – Industrial Processes and Products: Status Quo and Future Directions (Vols 1 and 2) Wiley–VCH 8 Organisation for Economic Co-operation and Development (OECD) (2001) The Application of Biotechnology to Industrial Sustainability, OECD Publications (http://www1.oecd.org/publications/e-book/ 9301061e.pdf) 9 Thomas, S.M. et al. (2002) Biocatalysis: applications and potentials for the chemical industry. Trends Biotechnol. 20, 238–242 10 Schmid, A. et al. (2001) Industrial biocatalysis today and tomorrow. Nature 409, 258–268 11 Breuer, M. et al. (2004) Industrial methods for the production of optically active intermediates. Angew. Chem. Int. Ed. 43, 788–824 12 Blaser, H.U. and Schmidt, E. (2003) Asymmetric Catalysis on Industrial Scale, Wiley–VCH 13 Sijbesma, F. (2003) White Biotechnology: Gateway to a More Sustainable Future, EuropaBio 14 Klibanov, A.M. (2001) Improving enzymes by using them in organic solvents. Nature 409, 241–246 15 Koeller, K.M. and Wong, C-H. (2001) Enzymes for chemical synthesis. Nature 409, 232–240 16 Compton, D.L. and King, J.W. (2001) Lipase-catalyzed synthesis of triolein-based sunscreens in supercritical CO2. J. Amer. Oil Chem. Soc. 78, 43–47 17 van Rantwijk, F. et al. (2003) Biocatalytic transformations in ionic liquids. Trends Biotechnol. 21, 131–138 18 Chotani, G. et al. (2000) The commercial production of chemicals using pathway engineering. Biochim. Biophys. Acta Mol. Cell Res. 1543, 434– 455 19 Madigan, M.T. and Marrs, B.L. (1997) Extremophiles. Sci. Am. 276, 82–87 20 Lorenz, P. et al. (2002) Screening for novel enzymes for biocatalytic processes: accessing the metagenome as a resource of novel functional sequence space. Curr. Opin. Biotechnol. 13, 572–577 21 Turner, N.J. (2003) Directed evolution of enzymes for applied biocatalysis. Trends Biotechnol. 21, 474–478 22 Zhao, H. et al. (2002) Directed evolution of enzymes and pathways for industrial biocatalysis. Curr. Opin. Biotechnol. 13, 104–110 23 Kerr, E. (2004) Broadened applicability of use for industrial enzymes. Genetic Engineering News 24, 1 24 Lorenz, P. and Zinke, H. (2005) White biotechnology: differences in US and EU approaches? Trends Biotechnol. 23, 570–574 25 Bachmann, R. and Riese, J. (2005) Industry overview: from promise to profit. Industrial Biotechnology 1, 9–15 26 Biermann, U. et al. (2000) New syntheses with oils and fats as renewable raw materials for the chemical industry. Angew. Chem. Int. Ed. 39, 2206–2224 27 Clark, J.H. (2006) Green chemistry: today (and tomorrow). Green Chem. 8, 17–21 28 Shonnard, D.R. et al. (2003) Industrial applications using BASF ecoefficiency analysis: perspectives on green engineering principles. Environ. Sci. Technol. 37, 5340–5348 29 International Organization for Standardization (1998) Life Cycle Assessment. ISO/TR 14041:1998, ISO 30 Vink, E.T.H. et al. (2003) Applications of life cycle assessment to NatureWorks polylactide (PLA) production. Polym. Degrad. Stabil. 80, 403–419 31 Gerngross, T.U. (1999) Can biotechnology move us toward a sustainable society? Nat. Biotechnol. 17, 541–544 32 Mattsson, B. et al. (2000) Agricultural land use in life cycle assessment (LCA): case studies of three vegetable oil crops.J. Clean.Prod.8, 283–292 33 Dornburg, V. et al. (2004) Comparing the land requirements, energy savings, and greenhouse gas emissions reduction of biobased polymers and bioenergy. An analysis and system extension of life-cycle assessment studies. J. Ind. Ecol. 7, 93–116 34 Mecking, S. (2004) Nature or petrochemistry? – biologically degradable materials. Angew. Chem. Int. Ed. 43, 1078–1085 35 Sakai, K. et al. (2004) Making plastics from garbage: a novel process for poly-L-lactate production from municipal food waste. J. Ind. Ecol. 7, 63–74 36 Heyde, M. (1998) Ecological considerations on the use and production of biosynthetic and synthetic biodegradable polymers. Polym. Degrad. Stabil. 59, 3–6 37 Petersson, A.E.V. et al. (2005) Wax esters produced by solvent-free energy-efficient enzymatic synthesis and their applicability as wood coatings. Green Chem. 7, 837–843 38 Gustafsson, L. and Bo¨rjesson, P. (2006) Life cycle assessment in green chemistry – a comparison of various wood surface coatings. Int. J. LCA DOI: 10.1065/lca2006.11.280 (http://www.scientificjournals.com/sj/lca/ onlineFirst) 39 Philips, M. (1991) Radiation Curing Systems, VCH 40 Crivello, J.V. and Narayan, R. (1992) Epoxidized triglycerides as renewable monomers in photoinitiated cationic polymerization. Chem. Mater. 4, 692–699 41 Overeem, A. et al. (1999) Seed oils rich in linolenic acid as renewable feedstock for environment-friendly crosslinkers in powder coatings. Ind. Crops Prod. 10, 157–165 42 Diehlmann, A. and Kreisel, G. (2000) Environmental audit for UV curable lacquers based on linseed oil. Farbe und Lack 106, 101–105 43 Swern, D. (1947) Electronic interpretation of the reaction of olefins with organic peracids. J. Am. Chem. Soc. 69, 1692–1698 44 Warwel, S. and Klaas, M.R. (1995) Chemoenzymic epoxidation of unsaturated carboxylic acids. J. Mol. Catal. B: Enzym. 1, 29–35 45 Orellana-Coca, C. et al. (2005) Chemo–enzymatic epoxidation of oleic acid and methyl oleate in solvent-free medium. Biocatal. Biotransfor. 23, 431–437 46 Buisman, G.J.H. (1999) Biodegradable binders and cross-linking agents from renewable resources. Surf. Coat. Int. 82, 127–130 47 To¨rnvall, U. et al. (2007) Stability of immobilized Candida antarctica lipase B during chemo–enzymatic epoxidation of fatty acid. Enzyme Microb. Tech. 40, 447–451 48 Ruettinger, R.T. and Fulco, A.J. (1981) Epoxidation of unsaturated fatty acids by a soluble cytochrome P450-dependent system from Bacillus megaterium. J. Biol. Chem. 256, 5728–5734 49 Derksen, J.T.P. et al. (1995) Paints and coatings from renewable resources. Ind. Crops Prod. 3, 225–236 50 Singh, S. et al. (2000) Inhibition of polyunsaturated fatty acid accumulation in plants expressing a fatty acid epoxygenase. Biochem. Soc. Trans. 28, 940–942 51 Thomaeus, S. et al. (2001) Distribution of fatty acids in polar and neutral lipids during seed development in Arabidopsis thaliana genetically engineered to produce acetylenic, epoxy and hydroxy fatty acids. Plant Sci. 161, 997–1003 52 Murphy, D.J. (2002) Biotechnology and the improvement of oil crops: genes, dreams and realities. Phytochem. Rev. 1, 67–77 124 Review TRENDS in Biotechnology Vol.25 No.3 www.sciencedirect.com