二氧化碳存在下甲烷氧化细菌催化甲烷生物合成甲醇

Biosynthesis of Methanol from Methane by Methanotrophic Bacteria in the Presence of Carbon Dioxide

在甲烷单加氧酶和脱氢酶系的作用下 ,甲烷氧化细菌MethylosinustrichosporiumIMV 30 11可以把甲烷氧化成二氧化碳 .在反应体系中充入一定比例的二氧化碳后 ,检测到了甲醇的积累 .混合气中CO2 ,CH4,O2 和N2 的体积比为 2∶1∶1∶1时甲醇的积累量达到最大 .在超滤膜反应器中进行了连续反应 ,利用反应混合气产生的压力将生成的甲醇从反应体系中分离 .连续反应

Methanotrophs can oxidize methane to carbon dioxide through sequential reactions catalyzed by a series of enzymes including methane monooxygenase, methanol dehydrogenase, formaldehyde dehydrogenase, and formate dehydrogenase. When a suspension of methanotrophic bacteria of Methylosinus trichosporium IMV 3011 was incubated at 32 ℃ with methane and oxygen, there was an extracellular accumulation of methanol from methane oxidation in response to the carbon dioxide addition. The maximal methanol accumulation was achieved when 40% carbon dioxide was in the mixed reaction gas. Continuous reaction was performed in an ultrafiltration membrane reactor and the optimum mixed gas containing 20% methane, 20% oxygen, 20% nitrogen and 40% carbon dioxide was used as substrates and to maintain the transmembrane pressure. The methanol product was removed by the eluate buffer. The initial methanol concentration in the eluate was 8 22 μmol/L. The bioreactor was allowed to operate continuously for 198 h without obvious loss of productivity.