Chapter 6 Microbial Metabolism Energy Metabolism Special Metabolism in Microbes The Relationship...
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Chapter 6 Microbial Metabolism • Energy Metabolism • Special Metabolism in Microbes • The Relationship between Catabolism and Anabolism • Regulation of Metabolism and Ferment Industry
Chapter 6 Microbial Metabolism Energy Metabolism Special Metabolism in Microbes The Relationship between Catabolism and Anabolism Regulation of Metabolism
Chapter 6 Microbial Metabolism Energy Metabolism Special
Metabolism in Microbes The Relationship between Catabolism and
Anabolism Regulation of Metabolism and Ferment Industry
Slide 2
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]
Slide 3
Section 1 Energy Metabolism in Microbes Primary Energy Organic
Compounds Sunlight Inorganic Compounds in Reduced State ATPATP ATP
Chemoheterotroph Photoautotroph Photoheterotroph Chemoautotroph
summarize
Slide 4
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
Slide 5
Slide 6
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
Slide 7
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
Slide 8
Uses pentoses and NADPH Operates with glycolysis 2)Hexose
Monophosphate Pathway (HMP) (Pentose Phosphate Pathway,
Phosphogluconate Pathway, Warburg-Dickens Pathway)
Slide 9
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
Slide 10
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
Slide 11
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
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
Slide 14
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
Slide 15
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
Slide 16
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
Slide 17
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
Slide 18
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:
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.
Slide 21
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.
Slide 22
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.
Slide 23
3 Respiration aerobic respiration anaerobic respiration 1.
Aerobic Respiration: The final electron acceptor in the electron
transport chain is molecular oxygen (O 2 ). Respiration
Slide 24
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)
Slide 25
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
Slide 26
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.
Slide 27
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.
Slide 28
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.
Slide 29
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
Slide 30
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)
Slide 31
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.
Slide 32
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
Slide 33
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
Slide 34
Section 2 special metabolism in microbes 1 Bacterial
Photosynthesis 1. Cyclic photophosphorylation 2. Noncyclic
photophosphorylation 3. Photosynthesis of purple membrane in
halophilic bacteria
Slide 35
purple sulfur bacteria: Chromatium purple nonsulfur bacteria:
Rhodospirillum, Rhodopseudomonas green sulfur bacteria: Chlorobium
green nonsulfur bacteria : Chloroflexus
Slide 36
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
Slide 37
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.
Slide 38
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.
Slide 39
noncyelic photophosphorylation
Slide 40
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 :
Slide 41
Slide 42
3) Photosynthesis of purple membrane in halophilic bacteria
Halobacterium uses bacteriorhodopsin, not chlorophyll, to generate
electrons for a chemiosmotic proton pump.
Slide 43
Slide 44
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
Slide 45
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
Slide 46
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
Slide 47
Slide 48
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
Slide 49
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
Slide 50
(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
Slide 51
Iron oxidizing bacteriaenergy-yielding process Iron oxidizing
bacteria: energy-yielding process by Oxidative Phosphorylation
Slide 52
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
Slide 53
3 Biologic Fixation of Nitrogen 1. Kinds of nitrogen fixing
microorganism Free-living nitrogen fixing bacteria Symbiosis
nitrogen fixing bacteria Association nitrogen fixing bacteria
Slide 54
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
Slide 55
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
Slide 56
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
Slide 57
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
Slide 58
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
Slide 59
N-acetylmuramic acid Parknucleotide Park Park nucleotide
hydrophilicity
Slide 60
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
Slide 61
Parknucleotide peptidoglycan unit in Bacterial Cytoplasm in
Bacterial Cytomembrane in outside of Bacterial Cytomembrane
Slide 62
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
Slide 63
Transglycosylation and Transpeptidation
Slide 64
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.
Slide 65
Microbial secondary metabolism and its product Regulation of
secondary metabolism 1 primary metabolism 2 nitric compound 3
induction and feedback inhibition
Slide 66
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.
Slide 67
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
Slide 68
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.
Using active metabolism in microbes 1 biotransformation, 2
microbial straw xylan-degrading, 3 microbiohydrometallurgy and oil
extraction, 4 biodegradation
Slide 72
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