上海交通大学：《微生物学 Microbiology》课程教学资源（双语课件）Lecture 13.2 Metabolic diversity（Chemolithotrophy）Chemolithotrophy：energy from the oxidation of inorganic electron donors 化能无机营养生物：通过氧化无机物而 获得能量

13.7 Hydrogen Oxidation 氢的氧化 Energetics of H2 oxidation ·H2+1/202→H20△G0=-237kJ ·catalyzed by hydrogenase.氢化酶 Autotrophy in H2 bacteria Most hydrogen bacteria can also grow as chemoorganotrophs,when growing chemolithotrophically they fix CO,by the Calvin cycle.多数氢细菌也是化能有机营养菌，当进 行化能无机自养时，通过卡尔文循环固定CO2 Chen Feng,Microbiology,SJTU

Chen Feng, Microbiology, SJTU 13.7 Hydrogen Oxidation 氢的氧化 Energetics of H2 oxidation • H2+1/2O2H2O G0’=-237kJ • catalyzed by hydrogenase.氢化酶 Autotrophy in H2 bacteria • Most hydrogen bacteria can also grow as chemoorganotrophs, when growing chemolithotrophically they fix CO2 by the Calvin cycle.多数氢细菌也是化能有机营养菌,当进 行化能无机自养时,通过卡尔文循环固定CO2

Membrane-integrated hydrogenase 2H+ H2 H 2Ht3-4H+ Out Need O,as terminal electron cyt bccytccyt aa3 accepter In 2H+ 2024Ht 2e- Some H2 bacteria have only the NAD++2 H+ H20 membrane-bound hydrogenase, CO2+ATP ADP ATP and in these organisms reducing NADH一 power synthesis occurs from Cytoplasmic hydrogenase reverse electron flow. Cell material Two hydrogenases: membrane-bound hydrogenase begins the flow of electrons leading to formation of a proton motive force. cytoplasmic hydrogenase makes NADH for the Calvin cycle.The membrane- bound hydrogenase

Two hydrogenases: membrane-bound hydrogenase begins the flow of electrons leading to formation of a proton motive force. cytoplasmic hydrogenase makes NADH for the Calvin cycle. The membrane￾bound hydrogenase Some H2 bacteria have only the membrane-bound hydrogenase, and in these organisms reducing power synthesis occurs from reverse electron flow. Need O2 as terminal electron accepter

13.8 Oxidation of reduced sulfur compounds还原态硫的氧化 Compounds used as electron donors: hydrogen sulfide(H2S),elemental sulfur(So), and thiosulfate(S2O32-). The final product of sulfur oxidation in most cases is sulfate (SO2-). Chen Feng,Microbiology,SJTU

Chen Feng, Microbiology, SJTU 13.8 Oxidation of reduced sulfur compounds 还原态硫的氧化 Compounds used as electron donors: hydrogen sulfide (H2S), elemental sulfur (S0 ), and thiosulfate (S2O3 2- ). The final product of sulfur oxidation in most cases is sulfate (SO4 2- )

Oxidation of Reduced Sulfur Compounds Electrons from reduced sulfur compounds reach the electron transport system Transported through the chain to O2 Usually aerobic,but some organisms can use nitrate as an electron acceptor Generates a proton motive force that leads to ATP synthesis by ATPase Chen Feng,Microbiology,SJTU

Chen Feng, Microbiology, SJTU Oxidation of Reduced Sulfur Compounds Electrons from reduced sulfur compounds reach the electron transport system • Transported through the chain to O2 • Usually aerobic, but some organisms can use nitrate as an electron acceptor • Generates a proton motive force that leads to ATP synthesis by ATPase

H+H+ 2H+ 3-4H+ Out Reverse e flow 3333333 NADFAD cyt bc cyt c cyt aaa In HS- S04 - S2032-ors9 Co2+ATP S0,2- Cell NADH ADP materia ATP () Need O,as terminal 2012 Pearson Education,Inc. electron accepter Electrons from sulfur compounds feed into the electron transport chain to drive a proton motive force;NADH must be made by reverse electron flow.通过电子传递链产生质子动势：通过反向电子 流产生NADH

Electrons from sulfur compounds feed into the electron transport chain to drive a proton motive force; NADH must be made by reverse electron flow.通过电子传递链产生质子动势;通过反向电子 流产生NADH Need O2 as terminal electron accepter