·Purple sulfur bacteria紫色硫细菌 -Use hydrogen sulfide (H2S)as an electron donor for CO2 reduction in photosynthesis Sulfide oxidized to elemental sulfur(So)that is stored as globules either inside or outside cells 硫氧化形成元素硫 Sulfur later disappears as it is oxidized to sulfate (SO) CHEN FENG,MICROBIOLOGY,SJTU
Chen Feng, Microbiology, SJTU • Purple sulfur bacteria 紫色硫细菌 – Use hydrogen sulfide (H2S) as an electron donor for CO2 reduction in photosynthesis – Sulfide oxidized to elemental sulfur (S0 ) that is stored as globules either inside or outside cells 硫氧化形成元素硫 • Sulfur later disappears as it is oxidized to sulfate (SO4 2 )
Figure 17.5 Bright-field and phase-contrast photomicrographs of purple sulfur bacteria. 288 86 8 00 6 合a。6mm所 (a) (b) 9 ⊙0 3 a (c) (d) 2012 Pearson Education,Inc
Figure 17.5 © 2012 Pearson Education, Inc. Bright-field and phase-contrast photomicrographs of purple sulfur bacteria
Purple sulfur bacteria (cont'd) Many can also use other reduced sulfur compounds,such as thiosulfate(S2O32-) -All are Gammaproteobacteria CHEN FENG,MICROBIOLOGY,SJTU
Chen Feng, Microbiology, SJTU • Purple sulfur bacteria (cont’d) – Many can also use other reduced sulfur compounds, such as thiosulfate (S2O3 2 ) – All are Gammaproteobacteria
Figure 17.6 (a) llaMpleo selbnog (c) Found in illuminated anoxic zones of lakes and other aquatic habitats where H2S accumulates,as well as sulfur springs 2012 Pearson Education,Inc CHEN FENG,MICROBIOLOGY,SJTU
Chen Feng, Microbiology, SJTU Figure 17.6 © 2012 Pearson Education, Inc. Found in illuminated anoxic zones of lakes and other aquatic habitats where H2S accumulates, as well as sulfur springs
Purple nonsulfur bacteria紫色非疏细菌 -Organisms able to use sulfide as an electron donor for CO2 reduction也可利用硫化物进行固碳 - Most can grow aerobically in the dark as chemoorganotrophs可进行有氧，呼吸 Some can also grow anaerobically in the dark using fermentation or anaerobic respiration 发酵或无氧呼吸 一 Most can grow photoheterotrophically using light as an energy source and organic compounds as a carbon source多数可行光能异养生活 -All in Alpha-and Betaproteobacteria CHEN FENG,MICROBIOLOGY,SJTU
Chen Feng, Microbiology, SJTU Purple nonsulfur bacteria紫色非硫细菌 – Organisms able to use sulfide as an electron donor for CO2 reduction 也可利用硫化物进行固碳 – Most can grow aerobically in the dark as chemoorganotrophs 可进行有氧呼吸 – Some can also grow anaerobically in the dark using fermentation or anaerobic respiration 也可 发酵或无氧呼吸 – Most can grow photoheterotrophically using light as an energy source and organic compounds as a carbon source多数可行光能异养生活 – All in Alpha- and Betaproteobacteria