Chloroform degradation in methanogenic methanol enrichment cultures and by Methanosarcina barkeri 227.
AUTOR(ES)
Bagley, D M
RESUMO
The effects of methanol addition and consumption on chloroform degradation rate and product distribution in methanogenic methanol enrichment cultures and in cultures of Methanosarcina barkeri 227 were investigated. Degradation of chloroform with initial concentrations up to 27.3 microM in enrichment cultures and 4.8 microM in pure cultures was stimulated by the addition of methanol. However, methanol consumption was inhibited by as little as 2.5 microM chloroform in enrichment cultures and 0.8 microM chloroform in pure cultures, suggesting that the presence of methanol, not its exact concentration or consumption rate, was the most significant variable affecting chloroform degradation rate. Methanol addition also significantly increased the number of moles of dichloromethane produced per mole of chloroform consumed. In enrichment cultures, the number of moles of dichloromethane produced per mole of chloroform consumed ranged from 0.7 (methanol consumption essentially uninhibited) to 0.35 (methanol consumption significantly inhibited) to less than 0.2 (methanol not added to the culture). In pure cultures, the number of moles of dichloromethane produced per mole of chloroform consumed was 0.47 when methanol was added and 0.24 when no methanol was added. Studies with [14C]chloroform in both enrichment and pure cultures confirmed that methanol metabolism stimulated dichloromethane production compared with CO2 production. The results indicate that while the addition of methanol significantly stimulated chloroform degradation in both methanogenic methanol enrichment cultures and cultures of M. barkeri 227, the prospects for use of methanol as a growth substrate for anaerobic chloroform-degrading systems may be limited unless the increased production of undesirable chloroform degradation products and the inhibition of methanol consumption can be mitigated.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=167597Documentos Relacionados
- Nitrogenase in the archaebacterium Methanosarcina barkeri 227.
- Interactions between Nitrogen Fixation and Osmoregulation in the Methanogenic Archaeon Methanosarcina barkeri 227
- Diazotrophy and Nitrogenase Activity in the Archaebacterium Methanosarcina barkeri 227
- Growth and Methanogenesis by Methanosarcina Strain 227 on Acetate and Methanol
- Methanogenic cleavage of acetate by lysates of Methanosarcina barkeri.