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Colorless Sulfur Bacteria. Blanca Pérez Hopkins Microbiology Course 2010. Colorless Sulfur Bacteria. Comprises a very heterogeneous group of chemoautotrophic bacteria Use of reduced forms of S as e- source
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Colorless Sulfur Bacteria Blanca Pérez Hopkins Microbiology Course 2010
Colorless Sulfur Bacteria • Comprises a very heterogeneous group of chemoautotrophic bacteria • Use of reduced forms of S as e- source • Most of them require O2 as e- acceptor, but a few are able to grow anaerobically using nitrogen oxides Sulfur cycle, Robertson and Keuenen (2006)
Thiobacillus Thiomicrospira Thiosphaera Sulfolobus Acidianus Thermothrix Thiovulum Beggiatoa Thiothrix Thioploca Thiodendron Thiobacterium Macromonas Achromatium Thiospira Will Colorless Sulfur Bacteria
Gradient tubes O2 Interface between opposing oxygen and sulfide gradients H2S H2S + 2O2 SO42- + 2H+
Gradient tubes Kosh
Gradient tubes Spirocheta sp. symbiotic relationships between Spirochaeta plicatilis with Beggiatoa Hyansoo
Thiosulfate plates • Use of thiosulfate as e- donor (with O2 or NO3- as e- acceptor) • Production of sulfuric acid (bromothymol blue) Anaerobic incubation (w NO3-) Aerobic incubation (w/o NO3-)
Thiosulfate plates: aerobic conditions 2 days Sulfuric acid Na2S2O3+ 2O2+ H2O Na2SO4+ H2SO4
Thiosulfate plates: anaerobic conditions ~2 weeks Sulfuric acid Elemental sulfur Aerobic incubation
Colorless Sulfur Bacteria Blanca Pérez Hopkins Microbiology Course 2010
Desulfovibrio sulfodismutans • can grow anaerobically by the disproportionation of thiosulfate to sulfate and sulfide • Sulfate Reducing Bacteria: disproportionation of thiosulfate