chapter 6 microbial metabolism energy metabolism special metabolism in microbes the relationship...

Chapter 6 Microbial Metabolism Energy Metabolism Special Metabolism in Microbes The Relationship between Catabolism and Anabolism Regulation of Metabolism and Ferment Industry

An Overview metabolism metabolism the sum total of all chemical reactions occurring in the cell metabolism catabolism anabolism Complex molecules catabolism anabolism Simple molecules ATP [H]

Section 1 Energy Metabolism in Microbes Primary Energy Organic Compounds Sunlight Inorganic Compounds in Reduced State ATPATP ATP Chemoheterotroph Photoautotroph Photoheterotroph Chemoautotroph summarize

The breakdown of glucose to pyruvate fermentation respiration aerobic or anaerobic respiration Chemoheterotroph biological oxidation and energy Release ProcessDehydrogenation, Giving Hydrogen and Accepting Hydrogen (Electron) FunctionReleasing Energy (ATP), Engendering Reducing Power [H] and Producing Intermediate Metabolites biological oxidation

Glocoserepresentative substrate of biological oxidation Embden-Meyerhof-Parnas Pathway (Glycolysis) Hexose Monophosphate Pathway Entner-Doudoroff Pathway (KDPG Pathway) PK (phosphoketolase) pathway 1 The breakdown of glucose to pyruvate

1 1 Embden-Meyerhof-Parnas Pathway (EMP) (Glycolysis, Hexose Diphosphate Pathway) glucose glucose pyruvate with connecte EMP pathway with TCA pathway with O 2 connecte EMP pathway with TCA pathway without reduce some metabolism product, only energy- yielding process. without O 2 reduce some metabolism product, only energy- yielding process. generates ATP by substrate-level phosphorylation generates ATP by substrate-level phosphorylation 1 glyceraldehyde 1,3-phosphate 3-phoshoglyceric acid + ATP 1 glyceraldehyde 1,3-phosphate 3-phoshoglyceric acid + ATP 2 PEP + ATP 2 PEP pyruvate + ATP Ten steps C 6 H 12 O 6 2NAD + 2ADP 2Pi 2CH 3 COCOOH 2NADH 2H + 2ATP 2H 2 O

Uses pentoses and NADPH Operates with glycolysis 2)Hexose Monophosphate Pathway (HMP) (Pentose Phosphate Pathway, Phosphogluconate Pathway, Warburg-Dickens Pathway)

fructose 6-phosphates be converted to glucose 6-phosphates be returned to be converted to glucose 6-phosphates be returned to Pentose Phosphate Pathway glyceraldehyde 3-phosphate a. through EMP pthway be converted to into TCA pthway a. through EMP pthway be converted to pyruvate into TCA pthway b. converted to, be returned to b. converted to Hexose Phosphate, be returned to Pentose Phosphate Pathway The overall reaction 6 glucose 6-phosphates + 12NADP + +3H 2 O 5 glucose 6- phosphates + 6CO 2 +12NADPH+12H + +Pi

3) Entner-Doudoroff Pathway (KDPG Pathway) 1952, Entner-Doudoroff Pseudomonas saccharophila process 4 septs glucose 6-phosphates 6-phosphogluconate 1 Glucose glucose 6-phosphates 6-phosphogluconate KDPG 6-phosphogluconate dehydratase glyceraldehyde 3-phosphate glyceraldehyde 3-phosphate + pyruvate 2-oxo-3-deoxy-6-phosphogluconate aldolase Produces NADPH and 1 ATP Does not involve glycolysis Pseudomonas, Rhizobium, Agrobacterium

4) phosphoketolase pathway (PK) a. a.Pentose phosphoketolas Pathway G xylulose 5-phosphate G xylulose 5-phosphate g 3-phosphate acetyl phosphate + glyceraldehyde 3-phosphate phosphoketolase ethanol pyruvate Lactic acid 1 G Lactic acid + ethanol + 1 ATP + NADPH + H+1 ATP

G fructose 6-phosphates G fructose 6-phosphates b.Hexose phosphoketolas Pathway (HK) Bifidobacterium bifidum -phosphates Erythrose - 4-P + acetyl-phosphates phosphoketolase glyceraldehyde 3-phosphate -phosphates glyceraldehyde 3-phosphate + acetyl-phosphates xylulose - xylulose -5-P ribulose-5-P Acetic acid phosphoketolase fructose 6-phosphates Lactic acid Acetic acid 1 G Lactic acid + 1.5 Acetic acid + 2.5 ATP ATP acetokinase

1. definitions 1. definitions broader use microorganism to produce useful metabolic product broader use microorganism to produce useful metabolic product narrower under anaerobic conditions, be defined as an energy- yielding process using itself metabolic intermediates as the final (electron) accepter narrower under anaerobic conditions, be defined as an energy- yielding process using itself metabolic intermediates as the final hydrogen (electron) accepter organic molecules serve as both electron donors and acceptors. organic molecules serve as both electron donors and acceptors. trait trait 1 generates ATP by substrate-level phosphorylation 1 generates ATP by substrate-level phosphorylation 2 the glucose is partially oxidized mostly energy in fermention products 2 the glucose is partially oxidized mostly energy in fermention products 3 lower energy 3 lower energy 4 generates many kinds of fermention products 4 generates many kinds of fermention products 2 fermentantion

2. fermentation sorts 1 alcohol fermentation a. yeasts 1 G 2 pyruvate 2 aldehyde + CO 2 2 ethanol + 2 ATP condiction pH 3.5~4.5, without O 2 Strain Saccharomyces cerevisiae, few bacteria( Erwinia amylovora, Sarcine vintriculi) I. Add NaHSO4 NaHSO4 + aldehyde sulfonic hydroxy aldehyde ii.weak basic pH 7.5 2 aldehyde 1 acetate + 1 ethanol glycerol fermentation : accepter, dihydroxyacetone as hydrogen accepter, hydrolyzed to glycerol EMP

b. bacteria (Zymomonasmobili, Pseudomonas saccharophila ) homo homoalcohol fermentation 1 G 2 1 G 2 pyruvate ED ethanol + 1ATP heteroalcohol fermentation ( Thermoanaerobacter ethanolicu ) 1 G 2 pyruvate Pyruvate formate lyase aldehyde ethanol formic acids + acetyl-CoA Without Pyruvatedecarboxylate With aldehyde dehydrogenase

2 Lactic acid fermentation Homolactate fermentation For example, Lactobacillus delbruckii, Streptococcus faecalis EMP pathway pyruvate lactate Heterolactate fermentation PK pathway Leuconostoc mesenteroides PK PK generates energy generates energy 1ATP Bifidobacterium bifidum PK HK PK generates energy generates energy 2G 5 ATP, 1G 2.5ATP

3) mixed acid, butanediol fermentation a.mixed acid fermentation E.coli, Salmonella, Shiella 1 G pyruvate lactate lactate dehydrogenase acetyl-CoA +formyl Pyruvate formate lyase oxaloacetate Propionic acid Methylmalonyl CoA carboxyltransferase phosphotransacetylase aldehyde dehydrogenase acetokinase Alcohol dehydrogenase acetateethanol CO 2 + H 2

b. butanediol fermentation Enterobacter, Serratia pyruvate acetolactate 3-hydroxy butanone diacetylRed substance dehydrogenase ) ( acetolactate dehydrogenase ) OH - O 2 neutral butanediol Two important reaction: 1. V. P. test 2. methylene red (M.R) test Enterobacter aerogenes: methylene red - E.coli: V.P. - , methylene red + V.P. test:

4) acetone- 4) acetone-butanol fermentation mixed, acetone: : ethanol = 3 6 1 mixed, acetone:butanol : ethanol = 3 6 1 Clostridium acetobutyricum Clostridium acetobutyricum 2 pyruvate 2 acetyl-CoA acetoacetyl-CoA acetone acetone +CO 2 acetate CoA transferase butanol acetyl-CoA acetyltransferase acetoacetate decarboxylase

5 stickland reaction Main point amino acid oxidation couples with other amino acids reduction, generates 1ATP hydrogen donors (oxidation ) amino acid: Ala, Leu, Ile, Val, His, Ser, Phe, Tyr, Try hydrogen acceptors (reduction) amino acid: Gly, Pro, Arg, Met, Leo, and so on.

The Stickland reaction is used to oxidize several amino acids: alanine, leucine, isoleucine, valine, phenylalanine, tryptophan, and histidine. Bacteria also ferment amino acids (e.g., alanine, glycine, glutamate, threonine, and arginine) by other mechanisms. The Stickland reaction is used to oxidize several amino acids: alanine, leucine, isoleucine, valine, phenylalanine, tryptophan, and histidine. Bacteria also ferment amino acids (e.g., alanine, glycine, glutamate, threonine, and arginine) by other mechanisms.

Oxidized glycine pyruvate -NH 3 NAD + NADH acetyl-CoA NAD + NADH acetate + ATP alanineacetatealanine -NH 3 Reduced one amino acid is oxidized and a second amino acid acts as the electron acceptor.

3 Respiration aerobic respiration anaerobic respiration 1. Aerobic Respiration: The final electron acceptor in the electron transport chain is molecular oxygen (O 2 ). Respiration

Give the substrate and products of the tricarboxylic acid cycle. To provide carbon skeletons for use in biosynthesis What chemical intermediate links glycolysis to the TCA cycle? The complete cycle appears to be functional in many aerobic bacteria, free- living protozoa, and most algae and fungi. 1 Tricarboxylic Acid Cycle (Krebs Cycle)

2 The Electron Transport Chain Some important electron transport chain carriers of the respiration chain in microbes Nicotianamide adenine dinucleotide (NAD) and nicotianamide adenine dinucleotide phosophate (NADP) Flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) Iron-sulphur protein Ubiquinone (Coenzyme Q) Cytochrome system

The Mitochondrial Electron Transport Chain. Many of the more important carriers are arranged at approximately the correct reduction potential and sequence. In the eucaryotic mitochondrial are organized into four complexes that are linked by coenzyme Q (I and cytochrome c (Cyt c). Electrons flow from NADH and succinl down the reduction potential gradient to oxygen.

Prokaryote The electron transport chain in Prokaryote Main outline: electron accepter multiplicity O 2, NO 3 -, NO 2 -, NO -, SO 4 2-, S 2-, CO 3 2- et al Electron donors H 2, S, Fe 2+, NH 4 +, NO 2 -, G, other orgnisim et al various cytochrome a, a1, a2, a4, b, b1, c, c1, c4, c5, d, o Terminal oxidase cyt a1, a2, a3, d, o catalase, peroxid enzyme Respiration Chain component variable, being branched respiration chain Bacterial chains also may be shorter and have lower P O ratios than mitochondrial transport chains from the several position of electron transport chain into and off by Terminal oxidase in several position. E.coli absent O 2 CoQ cyt.b556 cyt.o cyt.b558 cyt.d The cytochromes 0 branch has moderately high affinity for oxygen is a proton pump and operates at higher oxygen concentrations;The cytochromes d branch has very high affinity for oxygen and functions at low oxygen levels electron transport multiplicity.

3 Oxidative phosphorylqtion Chemiosmotic hypothesis Chemiosmotic hypothesis-first formulated in 1961 by the British biochemist Peter Mitchell. According to the Chemiosmotic hypothesis,the electron transport chain is organized so that protons move outward from the mitochondrial matrix and electrons are transported inward. Protons movement may result either from carrier loops,as shown in figure 9.14,or from the action of special proton pumps that derive their energy from electron transport. The result is proton motive force(PMF), composed of a gradient of protons and a membrane porential due to the unequal distribution of charges.When protons return to the mitochondrial matrix driven by the proton motive force,ATP is synthesized in a reversal of the ATP hydrolysis reaction.

The final electron acceptor in the electron transport chain is not O 2. Yields less energy than aerobic respiration because only part of the Krebs cycles operations under anaerobic conditions. Nitrate Respiration Denitrification Nitrate reduction outline a. have completely Respiration system reductase A and nitrous acid reductase needing for b. in the absence of O 2 only nitrate reductase A and nitrous acid reductase needing for Denitrification are induced. c. facultative anaerobic bacteria: Bacillus licheniformis, Paracoccus denitrificans, Pseudomonas aeruginosa and so on. 2. Anaerobic Respiration

Nitrate Respiration Homotype NO 3 - NH 3 - N R - NH 2 NO 3 - NH 3 - N R - NH 2 Hetertype use NO 3 - as the final in the absence of O 2 use NO 3 - as the final hydrongen accepter NO 3 - NO 2 NO N 2 O N 2 NO 3 - NO 2 NO N 2 O N 2 denitrification 1) make N NO3 - in soil reduced into N 2 and disappear, reduce edaphic fertility 2) 2) Denitrification has the importance action in nitrogen cycle. NiR 2 N 2 OR NOR NaR Facultative anaerobe (viz denitrify bacteriua)

Sulfate Respiration ( sulfate reduction in the absent of O 2,SO 4 2-, SO 3 2-, S 2 O 3 2- as the final electron accepter outline: a. obligate anaerobic bacteria b. mostly ancient bacteria c. mostil obligate chemoheterotroph few mixed d. end product: H 2 S SO 4 2- SO 3 2- SO 2 S H 2 S donorsdonors e. use organic nutrients organic acid, fatty acid, as hydrogen donors or electron donors f. environment contain SO 4 2-, anaerobic environment soil, seawater For example, Desulfovibrio desulfuricans, D Gigas, Desulfotomaculum nigrificans and so on.

Sulfur Sulfur reduction Sulfur Respiration Sulfur reduction use element Sulfur as the final electron accepter only. use element Sulfur as the final electron accepter only. electron donors aceticm acid, small peptide, glucose, carbohydrate polymers; electron donors aceticm acid, small peptide, glucose, carbohydrate polymers; For example, Desulfuromonas acetoxidans Carbonate Carbonate reduction Carbonate Respiration Carbonate reduction use CO 2 HCO 3 - as the final electron accepter use CO 2 HCO 3 - as the final electron accepter methane-producing bacteria: use H 2 as electron donors energy resources), CO 2 as accepter produce CH 4 ; use H 2 as electron donors energy resources), CO 2 as accepter produce CH 4 ; Producing acetic acid bacteria H 2 / CO 2 carry out product acetic acid H 2 / CO 2 carry out Anaerobic Respiration product acetic acid

other other anaerobic respiration use Fe 3+,Mn 2+, many organic oxide as the final electron accepter use Fe 3+,Mn 2+, many organic oxide as the final electron accepter succinate + 1 ATP fumaric acid succinate + 1 ATP For example, Escherichia, Proteus, Salmonella, Klebsiella in some facultative anaerobic bacteria, Bacteroides, Propionibacterium, Vibrio succinogenes in some anaerobic bacteria. Use Desulfotomaculum auripigmentum reduces AsO4 3- into As 2 S 3

Section 2 special metabolism in microbes 1 Bacterial Photosynthesis 1. Cyclic photophosphorylation 2. Noncyclic photophosphorylation 3. Photosynthesis of purple membrane in halophilic bacteria

purple sulfur bacteria: Chromatium purple nonsulfur bacteria: Rhodospirillum, Rhodopseudomonas green sulfur bacteria: Chlorobium green nonsulfur bacteria : Chloroflexus

The photosynthetic electron transport system in the purple nonsulfur bacterium, Rhodobacter sphaeroides. This scheme is incomplete and tentative. Ubiquinone (Q) is very similar to coenzyme Q. BPh stands bacteriopheophytin. NAD + and the electron source succinate are in color. Purple Nonsulfur Bacterial Photosynthesis. Cyclic photophosphorylation

Light energy is used to make ATP by cyclic photophosphorylation move electrons from sulfur donors (green and blue) to NAD+ (red). The electron transport chain has a quinone called menaquinone (MK). Green Sulfur Bacterial Photosynthesis. The photosynthetic electron transport system in the green sulfur bacterium, Chlorobium limicola.

2 noncyelic photophosphorylation 2 noncyelic photophosphorylation Electrons also can travel in a noncyclic pathway involving both photosystems. P700 is excited and donates electrons to ferredoxin as before. In the noncyclic route, however, reduced ferredoxin reduces NADP+ to NADPH. Electrons also can travel in a noncyclic pathway involving both photosystems. P700 is excited and donates electrons to ferredoxin as before. In the noncyclic route, however, reduced ferredoxin reduces NADP+ to NADPH. Because the electrons contributed to NADP+ cannot be used to reduce oxidized P700, photosystem II participation is required. It donates electrons to oxidized P700 and generates ATP in the process. Because the electrons contributed to NADP+ cannot be used to reduce oxidized P700, photosystem II participation is required. It donates electrons to oxidized P700 and generates ATP in the process. The photosystem II antenna absorbs light energy and excites P680, which then reduces pheophytin a. Pheophytin a is chlorophyll a in which two hydrogen atoms have replaced the central magnesium. The photosystem II antenna absorbs light energy and excites P680, which then reduces pheophytin a. Pheophytin a is chlorophyll a in which two hydrogen atoms have replaced the central magnesium. Electrons subsequently travel to Q (probably a plastoquinone) and down the electron transport chain to P700. Oxidized P680 then obtains an electron from the oxidation of water to O2. Electrons subsequently travel to Q (probably a plastoquinone) and down the electron transport chain to P700. Oxidized P680 then obtains an electron from the oxidation of water to O2.

noncyelic photophosphorylation

electrons flow from water all the way to NADP with the aid of energy from two photosystems, electrons flow from water all the way to NADP with the aid of energy from two photosystems, ATP is synthesized by noncyelic photophosphorylation. one ATP and one NADPH are formed when two electrons travel through noncyclic pathway. Outline :

3) Photosynthesis of purple membrane in halophilic bacteria Halobacterium uses bacteriorhodopsin, not chlorophyll, to generate electrons for a chemiosmotic proton pump.

2 Chemolithotroph Biological Oxidation, Energy Release and CO 2 Fixation in Chemoautotroph aerobic electron donors Oxidation of inorganic electron donors generates ATP by generates ATP by Oxidative Phosphorylation electron donors electron donors: H, reducing nitride, reducing sulphide and Fe 2 . Use CO 2 Fixation of Calvin cycle as carbon resources CO2 reduced to [CH 2 O] consume much energy and reducing power

1. Energy metabolism of nitribacteria Oxidation Nitrobacter: NH 3 NO 2 - Oxidation Nitrosomonas: NO 2 - NO 3 - When two genera such Nitrobacter and Nitrosomonas together in a niche, ammonia is grow converted to nitrate, a process called nitrification

2. Hydrogen oxidizing bacteria 2. Hydrogen oxidizing bacteria Main strains: Alcaligenes, Flavobacterium Aquaspirillum Mycobacterium Nocardia and so on. Alcaligenes, Flavobacterium Aquaspirillum Mycobacterium Nocardia and so on. generates energy 2H 2 + O 2 2 H 2 O generates energy 2H 2 + O 2 2 H 2 O synthesize reaction 2H 2 + CO 2 [ CH 2 O ] + H 2 O synthesize reaction 2H 2 + CO 2 [ CH 2 O ] + H 2 O

3.Sulfur Bacteria Energy Metabolism of Sulfur Bacteria Thiobacillus Energy source: Thiosulfate freely soluble in water and in the neutral condition. The respiratory chain of Thiobacilli: NADH 2 dehydrogenase, Fumaric reductase, flacoprotein FP , ubliquinone CoQ , cyt b, Cytochrome oxidase aa 3

energy-yielding process energy-yielding process : First sept: H 2 S, S 0, S 2 O 3 2 , oxidatived to SO 3 2 Second sept: SO 3 2 oxidatived to SO 4 2 and generates energy

(1) iron bacteria (iron oxidizing bacteria) Fe 2 into Fe 3 and generates energy. oxidative Fe 2 into Fe 3 and generates energy. For example, Ferrobacillus, Gallionella,Leptothrix,Crenothrix and Sphaerotilus; Ferrobacillus, Gallionella,Leptothrix,Crenothrix and Sphaerotilus; Thiobacillus frrooxidans: and Fe 2 Fe 3 so both iron bacteria. Thiobacillus frrooxidans: oxidative, S 0 and reducing sulphide, and Fe 2 oxidatived to Fe 3 so both Sulfur Bacteria and iron bacteria. mostly acidophilic mostly obligate Chemoautotrophic, few facultative Chemoautotrophic bacteria, acidophilic bacteria. 4 iron bacteria and bacterial leaching

Iron oxidizing bacteriaenergy-yielding process Iron oxidizing bacteria: energy-yielding process by Oxidative Phosphorylation

bacterial leaching (2) bacterial leaching Principle: a. 2S + 3O 2 + 2H 2 O 2H 2 SO 4 4FeSO 4 + 2H 2 SO 4 + O 2 2Fe 2 SO 4 3 + 2 H 2 O b. CuS + 2 Fe 2 SO 4 3 + 2H 2 O + O 2 CuSO 4 + 4FeSO 4 +2H 2 SO 4 c. CuSO 4 + Fe FeSO 4 + Cu

3 Biologic Fixation of Nitrogen 1. Kinds of nitrogen fixing microorganism Free-living nitrogen fixing bacteria Symbiosis nitrogen fixing bacteria Association nitrogen fixing bacteria

Supplying ATP Reducing Force [H] and its Carrier Nitrogenase (molebdoferredoxin, azoferredoxin) N 2 Mg 2+ Strict Anoxy microenvironment 2. The necessary condition of Nitrogen fixation

1966 M J Dilworth and R Scholhorn Nitrogenase: N 2 NH 3 N 2 ON 2 +H 2 O N 3- N 2 +NH 3 C 2 H 2 C 2 H 4 HCNCH 4 +NH 3 +[CH 3 NH 2 ] CH 3 NCCH 4 +CH 3 NH 2 +[C 2 H 4,C 2 H 6 ] 3.Determination of Nitrogenase Activity

4.The Biochemistry Pathway of Nitrogen Fixation N 2 +6e+6H + +12ATP2NH 3 +12ADP+12Pi 5.Hydrogen Reaction of Nitrogenase N 2 NH 3, 2H + H 2 N 2 +8H + +8e+16Mg-ATP2NH 3 +H 2 +16Mg-ADP+16Pi

A. The Protection Mechanism in Aerobic Free- living Nitrogen Fixting Bacteria a. Breathing Protection b. Conformation Protection B. The Protection Mechanism in Cyanobacteria a. Special Reducing Heterocysts Differentiated b. The Protection of Nitrogenase in Cyanobacteria that dont form heterocysts C. The Antioxygen Protection of Nitrogenase in Root Nodule Bacteria a. Symbiosis Rhizobia in Leguminous Plant b. Symbiosis Rhizobia in nonleguminous Plant 6. The antioxygen mechamism of Nitrogenase in Aerobic Nitrogen Fixing Bacteria

4 The Synthesis of Peptidoglycan A A The Synthesis in Bacterial Cytoplasm a G G-UDP M--UDP a G G-UDP M--UDP G 6- P- fructose 6-P- G 6- P- fructose 6-P- glucosamine N- -1- P N- acetoglucosamine -1- P N--UDP N- acetylglucosamine -UDP -UDP N-acetylmuramic acid -UDP b M Park UDP-M-pentapeptide b M Park nucleotide UDP-M-pentapeptide UDP as carrier sugar UDP as carrier sugar D-Val-D-Val are repressed by cycloserine D-Val-D-Val are repressed by cycloserine

N-acetylmuramic acid Parknucleotide Park Park nucleotide hydrophilicity

peptidoglycan unit synthesis Carrier bactoprenol carrier lipoid C55-isoprenol contain 11 isoprenoid units combinate to G during transmembrane link into interpeptide bridge; saccharide and carrier lipoid: concerned with the synthesize of polysaccharide and lipoidglycan in outer cell ( cellulose,polymannan, and so on vancomycin bacitracin inhibite some reactins B. The Synthesis in Bacterial Cytomembrane

Parknucleotide peptidoglycan unit in Bacterial Cytoplasm in Bacterial Cytomembrane in outside of Bacterial Cytomembrane

C.The Synthesis in outside of Bacterial Cytomembrane a. glycan chain extension transverse link : a. glycan chain extension transverse link : monomer+primer glycan chain transverse extense one disaccharide unit peptidoglycan monomer+primer glycan chain transverse extense one disaccharide unit b. Adjacent glycan chain connect vertical link : 2 D-Val M- tetrapeptide + D-Val 2 D-Val M- tetrapeptide + D-Val cross-links occur between the distalamino group of the diamino acid in the positon 3 of one stem peptide and D-alanine in the positon 4 of another stem peptide. cross-links occur between the distalamino group of the diamino acid in the positon 3 of one stem peptide and D-alanine in the positon 4 of another stem peptide. Transpeptidation repressed by penicillins, repressed by penicillins, penicillins : D-Val-D-Val analog, competitive t penicillins : D-Val-D-Val analog, competitive transpeptidase. Transglycosyl form -1 4 glucosidic bond

Transglycosylation and Transpeptidation

Section 3 microbial secondary metabolism and its product Section 3 microbial secondary metabolism and its product There are many kinds of secondary metabolite which primary metabolic products serve as substrate, some of these products have a considerable importance in fermentation industry. There are many kinds of secondary metabolite which primary metabolic products serve as substrate, some of these products have a considerable importance in fermentation industry. Metabolic adjustment of secondary metabolite is similar to primary metabolism, influenced by many factors. Metabolic adjustment of secondary metabolite is similar to primary metabolism, influenced by many factors.

Microbial secondary metabolism and its product Regulation of secondary metabolism 1 primary metabolism 2 nitric compound 3 induction and feedback inhibition

Section 4 Regulation of metabolism and ferment product practise. Metabolic regulation kinds are various, microorganism produce metabolic product to offer service for fermentation industry and to benefit for mankind with their relevant knowledge of adjusting control. Metabolic regulation kinds are various, microorganism produce metabolic product to offer service for fermentation industry and to benefit for mankind with their relevant knowledge of adjusting control.

Using microbial metabolic product Metabolic product type 1 primary metabolic products: amino acid, enzyme or coenzyme 2 submetabolic products: antibiotic, hormone, alkaloid, toxin, vitamin, and so on. Fermentation type Fermentation type fermentation 1 Natural fermentation : ethanol, lacate and so on fermentation 2 Metabolic control fermentation: terminal products: lysine, guanylic acid, adenylic acid and so on metabolic intermediates: metabolic intermediates: citrate,-ketoglutaric acid, succinate,inosinic acid,xanthine nucleotide and so on

Control of ferment condiction 1 cultrue condition temperature, pH and so on; 2 nutrition component glucose concentration, C/N, growth factor, and so on; 3 dissolved oxygen: aeration numbr, agitation and so on.

Control of Metabolic regulation 1 auxotrophic regulatory mutant fermentation ( homoserine auxotrophic mutant ) Lysine fermentation ( homoserine auxotrophic mutant )

Microbial metabolism and Metabolic engneering Metabolic Engineering introduce xylose Metabolic pathway Xylose xylitol Xylulose Xlulokinase Xylulose-5-P Glucose Pyruvate Ethanol Xylose isomerase Xylose reductase xylitol dehydrogenase Pentose phosphoketolas Pathway Pichia stipitis bacteria Glycolysis Entner- Doudoroff Pathway

Using active metabolism in microbes 1 biotransformation, 2 microbial straw xylan-degrading, 3 microbiohydrometallurgy and oil extraction, 4 biodegradation

References: Prescott LM, Harley JP, and Klein DA. Microbiology (5th ed.), Higher education press and McGraw-Hill Companies, Inc.2002 Michael TM, John MM, Jack P. Brock biology of micoorganisms International edition, Pearson Education, Inc.2003 Talaro K. P. Foundations in microbiology (Fifth Edition), Higher education press and McGraw-Hill Companies, Inc.2005

chapter 6 microbial metabolism energy metabolism special metabolism in microbes the relationship...

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