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Microbial sulfur cycle. Some bacteria use light energy to couple sulfur oxidation to carbon dioxide (CO 2) fixation for growth. These fall into two general groups: green sulfur bacteria (GSB) and purple sulfur bacteria (PSB). [6] However, some Cyanobacteria are also able to use hydrogen sulfide as an electron donor during anoxygenic ...
Instead, they can use sulfur in the form of sulfide, or thiosulfate (as well, some species can use H 2, Fe 2+, or NO 2 −) as the electron donor in their photosynthetic pathways. [5] The sulfur is oxidized to produce granules of elemental sulfur. This, in turn, may be oxidized to form sulfuric acid.
Sulfuric(IV) acid (United Kingdom spelling: sulphuric(IV) acid), also known as sulfurous (UK: sulphurous) acid and thionic acid, [citation needed] is the chemical compound with the formula H 2 SO 3. Raman spectra of solutions of sulfur dioxide in water show only signals due to the SO 2 molecule and the bisulfite ion, HSO − 3 . [ 2 ]
The important sulfur cycle is a biogeochemical cycle in which the sulfur moves between rocks, waterways and living systems. It is important in geology as it affects many minerals and in life because sulfur is an essential element (), being a constituent of many proteins and cofactors, and sulfur compounds can be used as oxidants or reductants in microbial respiration. [1]
Anaerobic, anoxygenic photosynthesis Fry et al. (1985) [77] Elemental sulfur Sulfate Ectothiorhodospira shaposhnikovii (purple sulfur bacteria) ±5‰ (no temperature provided) Anaerobic, anoxygenic photosynthesis Ivanov et al. (1976) [78] Polythionates (S n O 6 2-) Elemental sulfur Sulfate Chromatium sp. (purple sulfur bacteria) 4.9 to 11.2 ...
Purple bacteria use bacteriochlorophyll and carotenoids to obtain the light energy for photosynthesis. Electron transfer and photosynthetic reactions occur at the cell membrane in the photosynthetic unit which is composed by the light-harvesting complexes LHI and LHII and the photosynthetic reaction centre where the charge separation reaction ...
The energy of P680 + is used in two steps to split a water molecule into 2H + + 1/2 O 2 + 2e-(photolysis or light-splitting). An electron from the water molecule reduces P680 + back to P680, while the H + and oxygen are released.
Oxaloacetic acid or malate synthesized by this process is then translocated to specialized bundle sheath cells where the enzyme RuBisCO and other Calvin cycle enzymes are located, and where CO 2 released by decarboxylation of the four-carbon acids is then fixed by RuBisCO activity to the three-carbon 3-phosphoglyceric acids.