Methanogenesis from Sucrose by Defined Immobilized Consortia
AUTOR(ES)
Jones, W. Jack
RESUMO
A bacterial consortium capable of sucrose degradation primarily to CH4 and CO2 was constructed, with acetate as the key methanogenic precursor. In addition, the effect of agar immobilization on the activity of the consortium was determined. The primary fermentative organism, Escherichia coli, produced acetate, formate, H2, and CO2 (known substrates for methanogens), as well as ethanol and lactate, compounds that are not substrates for methanogens. Oxidation of the nonmethanogenic substrates, lactate and ethanol, to acetate was mediated by the addition of Acetobacterium woodii and Desulfovibrio vulgaris. The methanogenic stage was accomplished by the addition of the acetophilic methanogen Methanosarcina barkeri and the hydrogenophilic methanogen Methanobacterium formicicum. Results of studies with low substrate concentrations (0.05 to 0.2% [wt/vol]), a growth-limiting medium, and the five-component consortium indicated efficient conversion (40%) of sucrose carbon to CH4. Significant decreases in yields of CH4 and rates of CH4 production were observed if any component of the consortium was omitted. Approximately 70% of the CH4 generated occurred via acetate. Agar-immobilized cells of the consortium exhibited yields of CH4 and rates of CH4 production from sucrose similar to those of nonimmobilized cells. The rate of CH4 production decreased by 25% when cysteine was omitted from reaction conditions and by 40% when the immobilized consortium was stored for 1 week at 4°C.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=239601Documentos Relacionados
- Methanogenesis from Ethanol by Defined Mixed Continuous Cultures
- Cloning of Sucrose:Sucrose 1-Fructosyltransferase from Onion and Synthesis of Structurally Defined Fructan Molecules from Sucrose1
- The production of sorbitol by permeabilized and immobilized cells of Z. mobilis in sucrose
- Bioenergetics of methanogenesis from acetate by Methanosarcina barkeri.
- Uncoupling of Methanogenesis from Growth of Methanosarcina barkeri by Phosphate Limitation