上泽充通大￥ Shanghai Jiao Tong University 1896 1920 1987 2006 Lecture 16-3 Microbial Evolution and Systematics 微生物进化与系统分类 Chapter 16 in BROCK BIOLOGY OF MICROORGANISMS AI JIAO TONG UNI Chen Feng School of Life Science and Technology Shanghai Jiao Tong University
1896 1920 1987 2006 Lecture 16-3 Microbial Evolution and Systematics 微生物进化与系统分类 Chen Feng School of Life Science and Technology Shanghai Jiao Tong University Chapter 16 in BROCK BIOLOGY OF MICROORGANISMS
III.Microbial Systematics微生物系统 分类学 @Phylogenetics系统发生学-the study of phylogeny family history of microbes ·Genotype-based Taxonomy:分类学-science of classification, consists of two major subdisciplines: 。Identification鉴定 ·Nomenclature命名 ·Phenotype-based Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University III. Microbial Systematics微生物系统 分类学 Phylogenetics系统发生学-the study of phylogeny • family history of microbes • Genotype-based Taxonomy分类学-science of classification, consists of two major subdisciplines: • Identification 鉴定 • Nomenclature 命名 • Phenotype-based
Conventional/Classical Taxonomy 传统/经典分类法 Characteristics of taxonomic value include Morphology,Motility,Nutrition, Pysiology&Ecology?分类学特征包括形态学、 运动性、营养需求、生理学、生态学特征 GC ratios can be a part of classical bacterial taxonomy Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University Conventional/Classical Taxonomy 传统/经典分类法 Characteristics of taxonomic value include Morphology, Motility, Nutrition, Pysiology & Ecology分类学特征包括形态学、 运动性、营养需求、生理学、生态学特征 GC ratios can be a part of classical bacterial taxonomy
Isolation of bacterium from intestine of warm-blooded animal Example of methods for Obtain pure culture identification鉴定方法举例 Most of the analyses require: Gram reaction ↓ 1.pure culture of the organism Gram-negative 2.solely phenotypic criteria Rod-shaped 鉴定中需要纯培养物和独特的表型特 征 Facultative ↓ Ferments lactose, producing acids and gas ↓ Perform biochemical tests: (Positive:indole,methyl red,mucate; Identification negative:citrate,Voges-Proskauer,H2S) Escherichia coli
Example of methods for identification 鉴定方法举例 Most of the analyses require： 1. pure culture of the organism 2. solely phenotypic criteria 鉴定中需要纯培养物和独特的表型特 征 Identification
16.10 Phenotypic Analysis:Fatty Acid Methyl Ester(FAME)脂肪酸甲酯分析法 FAME:Identification through characterizations of the types and proportions of fatty acids present in membrane and outer membrane(G-) lipids of cells.通过细胞膜/外膜的脂肪酸类型 来鉴定细菌 More than 200 different fatty acids have been discovered from bacterial sources. Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University 16.10 Phenotypic Analysis: Fatty Acid Methyl Ester (FAME) 脂肪酸甲酯分析法 FAME: Identification through characterizations of the types and proportions of fatty acids present in membrane and outer membrane (G- ) lipids of cells.通过细胞膜/外膜的脂肪酸类型 来鉴定细菌 More than 200 different fatty acids have been discovered from bacterial sources
Classes of Fatty Acids in Bacteria Class/Example Structure of example 0 l. Saturated: C-(CH2)12-CH3 tetradecanoic acid HO HH II.Unsaturated: C-(CH2)6-C=C-(CH2)6-CH3 omega-7-cis hexadecanoic acid HO 0 CH2 III.Cyclopropane: cis-7,8-methylene C-(CH2)7-C-C-(CH2)5-CH3 hexadecanoic acid HO HH IV.Branched: 13-methyltetradecanoic acid HO -( HCHg 0 H V.Hydroxy: C-CH2-C-(CH2)10-CH3 3-hydroxytetradecanoic acid HO OH (a) 2012 Pearson Education.Inc
FAME Analysis Procedure IDENTIFY ORGANISM ↑ Compare pattern of peaks with patterns in database Bacterial culture Extract fatty acids Peaks from various fatty acid methyl esters Derivatize to form methyl esters Gas chromatography (b) 2012 Pearson Education,inc Each peak from the gas chromatograph is due to one particular fatty acid methyl ester and the peak height is proportional to the amount
FAME Analysis Procedure Each peak from the gas chromatograph is due to one particular fatty acid methyl ester and the peak height is proportional to the amount
16.11 Genotypic Analyses Genomic hybridization as a taxonomic tool基因组杂交法 Organisms to organism 1 Organism 2 be compared: ↓ Genomic DNA Genomic DNA ↓ ↓ DNA preparation Shear and label®) Shear DNA Iee官 Heat to form single ®® strands (a) 2012 Pearson Education,Inc. a)DNA is isolated from test organisms.One of the DNAs is labeled (Organism 1)
Chen Feng, Shanghai Jiao Tong University 16.11 Genotypic Analyses Genomic hybridization as a taxonomic tool 基因组杂交法 a) DNA is isolated from test organisms. One of the DNAs is labeled (Organism 1)
Hybridization experiment: Mix DNA,adding unlabeled DNA in excess: ® 1X1 Hybridized DNA- 1×2 Hybridized DNA- (b) 2012 Pearson Education.Inc. (b)hybridization experiment. Excess unlabeled DNA is added in each experiment to prevent labeled DNA from reannealing with itself.Following hybridization,hybridized DNA is separated from unhybridized DNA before measuring radioactivity in the hybridized DNA only
(b) hybridization experiment. Excess unlabeled DNA is added in each experiment to prevent labeled DNA from reannealing with itself. Following hybridization, hybridized DNA is separated from unhybridized DNA before measuring radioactivity in the hybridized DNA only
Results and interpretation: Same genus, 1X1 1X2 Same but different Different 100% <25% species species genera 100 75 50 25 0 Same strain 1 and 2 are likely Percent hybridization (control) different genera (c) 2012 Pearson Education,Inc. c)Results.Hybridization values of 70%or above=the same species; values of at least 20-30%two organisms in same genus. Hybridization of DNAs from totally unrelated organisms occurs at less than 10%
c) Results. Hybridization values of 70% or above the same species; values of at least 20-30% two organisms in same genus. Hybridization of DNAs from totally unrelated organisms occurs at less than 10%