Chapter 1 1.3 Choice of production process economic It is possible to produce many chemical moieties(partly) by means of bi technological nsiderations production processes. For example, ethene(C)H commands a large market and is produced from fossil oil. This chemical can also be produced from ethanol, which in building unit for the petrochemical industry from which several other intermediates and end products such as plastics are produced. The biotechnological production method is, however, for economical reasons still not used in practice. The costs of producing ethene from sugar via ethanol are relatively too high. This is partly due to the cost of the raw materials and the product yields on the two different substrates. The eparation of ethanol from the aqueous fermentation liquid is also relatively expensive Unfortunately micro-organisms that make large amounts of ethene directly from glucose have not been found. Nevertheless, the biotechnological production method may become the cost effective option as fossil energy sources become depleted and relatively more expensive. Other chemicals such as gluconic acid cannot be produced by petrochemical production methods. Gluconic acid is used in the pharmaceutical industry and even as an addition to concrete. Gluconic acid can be produced from glucose, derived from potato starch, using the bacterium Gluconobacter or the fungus Aspergillus. These micro-organisms are able to modify glucose rapidly to gluconic acid, which is slowly consumed again. In this way gluconic acid is temporarily accumulated in the fermentation fluid. Technically, it specificity of would be possible to perform this process chemically starting from glucose, but in this thus no undesired byproducts are formed. For the same reason biotechnological production processes are preferred if optically pure chiral compounds, such as L-configuration of a certain amino acid, has to be produced. The price of such products production of organic acids andam sive. In later chapters of this text we consider the is, however, relatively more exper ino acids in some detail biodegradable Another example of producing a chemical in bulk from sugar with the help of a products micro-organism is the polymer polyhydroxybutyric acid. Many micro-organisms accumulate this compound as a reserve material. This polymer could be substitute for polyester or polypropene plastics. The big advantage of polyhydroxybutyric acid is that it can be degraded microbially. Products such as plastics that have been used for shorter or longer times and when they are not needed any more are brought back into the environment. However, when retumed to the environment they are not readily biodegraded (they are recalcitrant)and thus accumulate. The accumulation of materials that are not readily returned to natural geocycling is of major concern. In a world where mankind has become aware that more sustainable environmental practice have to be used to prevent pollution, biotechnology will become more and more important. A first obvious consequence of such considerations is that we should not only look at the costs of the product from an economic point of view, but that we must consider the costs of the production process in a broader sense. We must take into account the raw materials used, the amount of energy invested and the possibility to design alternatives, more environmentally friendly processes. In other words, we should not only look at the desired product, but we must consider the total life cycle of the product. The design manage f a production process taking into account these aspects is often referred to as integral life cycle management.4 Chapter 1 economic COnsidetations specificity of readon biodegradable pro&* 1.3 Choice of production process It is possible to produce many chemical moieties (partly) by means of biotechnological production processes. For example, ethene (Cd-h) commands a large market and is produced from fossil oil. This chemical can also be produced from ethanol, which in turn can be produd by micro-organisms using agricultural wastes. Ethene is a 'building unit' for the petrochemical industry from which several other intermediates and end products such as plastics are produced. The biotechnological production mthM is, however, for economical reasons still not used in practice. The costs of producing ethene from sugar via ethanol are relatively too high. This is partly due to the cost of the raw materials and the product yields on the two different substrates. The separation of ethanol from the aqueous fermentation liquid is also relatively expensive. Unfortunately micmrganisms that make large amounts of ethene directly from glucose have not been found. Nevertheless, the biotechnological production method may become the cost effective option as fossil energy sources become depleted and relatively more expensive. Other chemicals such as gluconic acid cannot be produced by petrochemical production methods. Gluconic acid is used in the pharmaceutical industry and even as an addition to concrete. Gluconic acid can be produced from glucose, derived from potato starch, using the bacterium Gluconobucfer or the fungus Aspergillus. These micro-organisms are able to modify glucose rapidly to gluconic acid, which is slowly consumed again. In this way gluconic acid is temporarily accumulated in the fermentation fluid. Technically, it would be possible to perform this process chemically starting from glucose, but in this case the biological method is preferred as the specifity of this reaction is very high and thus no undesired byproducts are formed. For the same reason biotechnological production processes are preferred if optically pure chiral compounds, such as Lconfiguration of a certain amino acid, has to be produced. The price of such products is, however, relatively more expensive. In later chapters of this text we consider the production of organic acids and amino acids in some detail. Another example of producing a chemical in bulk from sugar with the help of a micro-organism is the polymer polyhydroxybutyric acid. Many micmorganisms accumulate this compound as a reserve material. This polymer could be substitute for polyester or polypropene plastics. The big advantage of polyhydroxybutyric acid is that it can be degraded microbially. Products such as plastics that have been used for shorter or longer times and when they are not needed any more are brought back into the environment. However, when returned to the environment they are not readily biodegraded (they are recalcitrant) and thus accumulate. The accumulation of materials that are not readily returned to natural geocycling is of mapr concern. In a world where mankind has become aware that more sustainable environmental practice have to be used to prevent pollution, biotechnology will become more and more important. A first obvious consequence of such considerations is that we should not only look at the costs of the product from an economic point of view, but that we must consider the costs of the production process in a broader sense. We must take into account the raw materials used, the amount of energy invested and the possibility to design alternatives, more environmentally friendly processes. In other words, we should not only look at the desired product, but we must consider the total life cycle of the product. The design of a production process taking into account these aspects is often referred to as integral life cycle management