Chapter 3 SAQ 3.1 a bacterium is grown aerobically with glucose as sole source of carbon and ammonium ions as nitrogen source. Experimental analysis shows that six moles of glucose are utilised for each mole of biomass produced. Write the reaction equation for growth if the elemental composition of the cells is CH16 Oz Nozo. (Hint: commence with the'abstract equation E-3.1) For a more detailed stoichiometric representation for aerobic growth of a chemoheterotrophic organism we must consider generation and utilisation of ATP the oxidation-reduction balance of substrates and products. This allows an assessment of the relative efficiencies of the biochemical pathways involved in microbial growth and metabol It may be assumed that neither ATP nor NADH accumulates, ie formation must be balanced by utilisation. Let us first consider the formation and utilisation of ATP;we ergy ATP formation AtP utilisation (substrate level phosphorylation (oxidative phosphorylation (maintenance and dissipate For substrate level phosphorylation we can writ e。a(ADP+P)→Ea(ATP+H2O) E-3.2 Where: Es=number of substrate-level phosphorylations per mole of carbon utilised For oxidative phosphorylation we can write: 2b(P/O)(ADP +Pi)-2b(P/O)(ATP H2O) E-33 Where: P/O=is the number of ADP phosphorylations per atom of oxygen consumed For biosynthesis(ATP utilisation)we can write MW MW 又(ATP+H2O) (ADP+ Pi ATP ATP E-34 Where y me omass mass of cells formed per mol of atp utilised in biosynthesis40 Chapter 3 A bacterium is grown aerobically with glucose as sole source of carbon and armnoNum ions as nitrogen source. Experimental analysis shows that six moles of glucose are utilised for each mole of biomass produced. Write the reaction equation for growth if the elemental composition of the cells is CHI.& QZNO^. (Hint: commence with the 'abstract' equation E - 3.1). ~~ For a more detailed stoichiometric representation for aerobic growth of a chemoheterotrophic organism we must consider: 0 the generation and utilisation of ATP; the oxidation-reduction balance of substrates and products. This allows an assessment of the relative efficiencies of the biochemical pathways involved in microbial growth and metabolism. It may be assumed that neither ATP nor NADH accumulates, ie formation must be balanced by utilisation. Let us first consider the formation and utilisation of ATP; we may write: energy ATP formation = ATPutilisation balance (substrate level phosphorylation) (biosynthesis) (oxidative phosphorylatioQ (maintenance and dissipation) For substrate level phosphorylation we can write: ES a (ADP + PI) + G a (ATP + Ha) E - 3.2 Where: cs = number of substrate-level phosphorylations per mole of carbon utilised. For oxidative phosphorylation we can write: 2b (P/O) (ADP + PI) + 2b V/O) (ATP + H20) E - 3.3 Where: P/O = is the number of ADP phosphorylations per atom of oxygen consumed. For biosynthesis (ATP utilisation) we can write: MWB (ADP+PJ MWB y ,,(ATP + HD) + - Y Inax ATP ATP Where: MWB = molecular weight of biomass; Y ATP = mass of cells formed per mol of ATP utilised in biosynthesis. E - 3.4 max