Microbial Metabolism Anabolism -...

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Microbial MetabolismAnabolismChing-Tsan Huang (黃慶璨)Office: Agronomy Hall, Room 111Tel: (02) 33664454E-mail: cthuang@ntu.edu.tw

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Overview of Anabolism

http://lecturer.ukdw.ac.id/dhira/Metabolism/Anabolism.html

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PhotosynthesisPhototrophs• Photoautotrophs: CO2 as carbon source• Photoheterotrophs: Organic carbon as carbon

source

Light reaction• light energy is trapped and converted to chemical

energy

Dark reaction• reduce or fix CO2 and synthesize cell constituents

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Energy Trapping

Oxygenic

Anoxygenic

Oxygenic Anoxygenic

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Light ReactionChlorophyll and bacteriochlorophyllRequired in photosynthesis

Photosynthetic membranesFound inside the cell membrane and

include chlorophyll pigments and other light-gathering apparatus

Eucaryotes & Cyanobacteria

Green & Purple Bacteria

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Light ReactionReaction centerParticipate directly in the conversion of light energy to ATP

Antenna pigmentsHarvest light energy and funnel to the reaction center (RC)

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Electron flow in photosynthesis

Oxygenic Anoxygenic

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Overview of Photosynthesis

Source: U.S. Department of Energy Genome Programs http://genomics.energy.gov.

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Autotrophsobtain energy by trapping light during photosynthesis or by oxidizing or reduced inorganic electron donors

Calvin cycle• Purple bacteria,

cyanobacteria, algae and green plants 6 RuBP + 6 CO2

12 PGA6 RuBP + Fructose 6-P

Prescott et al. Microbiology 5th, 2002

Autotrophic fixation of CO2

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Autotrophic fixation of CO2

Reverse citric acid cycleGreen sulfur bacteria

Hydroxypropionate pathway

• Green nonsulfur bacteria

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MethyltrophyC1 Assimilation

The serine pathway

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MethyltrophyC1 Assimilation

The ribulose monophosphate pathway

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Synthesis of pyruvate to glucose Gluconeogenesis: Heterotrophs synthesize sugars by reducing organic molecules

Glucoeogenesis Glycolysis

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Synthesis of SugarsGluconeogenesis synthesize glucose and fructose from

noncarbohydrate precursors

Sugar nucleoside diphosphates synthesis of other sugars ,

polysaccharides, and bacterial cell walls

ATP + glucose 1-P ADP-glucose + PPi

(glucose)n + ADP-glucose (glucose)n+1 + ADP

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Synthesis of Polysaccharides

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Synthesis of amino acids

Oxaloacetate

Phosphoenolpyruvate

-ketoglutarate

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Lipid synthesisTriacrylglycerols & phospholipids

Fatty acid synthesis

ACP: acryl carrier protein