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HMC 2012 Enrichments & Isolations Presentation. Clostridia Enrichment. Guangfei Liu. Clostridium (Kloster/ klwshr , Spindle). 梭 Shuttle. Endospores.
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HMC 2012 Enrichments & Isolations Presentation Clostridia Enrichment Guangfei Liu
Clostridium (Kloster/klwshr,Spindle) 梭 Shuttle
Endospores Clostridium is a genus of Gram-positive bacteria, belonging to the Firmicutes. They are obligate anaerobes capable of producing endospores Tortora et al. 2008. Microbiology An Introduction, 10th edition.
37 °C The Enrichment
Pectins Utilization Galactouronic acid Pectins Pectins are linear polysaccharides derived from galactouronic acid units, where some of the carboxylic acid groups are esterified with methanol. During fermentation, the ester groups are hydrolyzed, and methanol is released
Methanol was the major nongaseous end product produced by some of the species examined. For C. buwricum strain 4P1 on pectin (mM): 16, methanol; 11.4, butyrate; 7.5, acetate; 2.3, ethanol; 0.8, lactate; and 0.7, isopropanol. The methanol produced by the species examined here was not further consumed. In control experiments, these species did not grow on methanol as energy source.
37 °C 80 °C Inoculation and Incubation
+ CO2 GYT Broth (g/L): 10.0 glucose; 5.0 tryptone; 10.0 yeast extract; 0.5 Na-thioglycolate; 20.0 CaCO3. Fermentation of glucose by Clostridia. Glucose is degraded to pyruvate via the Embden-Meyerhof pathway Lengeler et al. (2009) Biology of the Prokaryotes
3 ATP Butyrate- + 2CO2 + 2H2 + H+ ΔG°’= -255 kJ/mol glucose (85 kJ/mol ATP) Glucose 4 ATP 2Acetate-+ 2CO2 + 4H2 + 2H+ ΔG°’= -206 kJ/mol glucose (52 kJ/mol ATP) Glucose + 2H2O 3.3 ATP 0.7 Butyrate- +0.6 Acetate-+ 2CO2 + 2.6 H2 + 1.3 H+ ΔG°’= -240 kJ/mol glucose (71 kJ/mol ATP) Glucose
Acid Production and Catalase Test Propionic-acid-bacteria Clostridia Negative Positive