甲基弯菌IMV 3011整细胞催化甲烷氧化合成甲醇的研究

Biosynthesis of Methanol from Methane by Whole Cell of Methylosinus Trichosporium IMV 3011

研究了在甲基弯菌(Methylosinustrichosporium)IMV3011整细胞催化甲烷制甲醇的反应过程中,菌体浓度、阻断剂乙二胺四乙酸(ethylenediaminetetraaceticacid,简称EDTA)浓度、外源性电子给体、混合气组分及压力与甲醇积累的关系.批式反应的实验结果表明,在菌体浓度为7.4mg/mL时,以2mmol/LEDTA作阻断剂效果最好;作为电子给体,甲酸钠(20mmol/L)的效果优于琥珀酸钠(40mmol/L),使用前者时的甲醇积累量是用后者时的2.8倍左右;当甲烷与空气的体积比为1∶1.7时,转化率为6.0%,甲醇积累量最大;压力选用0.16MPa.连续反应中,于培养基中无铜离子培养的细胞与有铜离子的相比,持续时间长,甲醇积累高(最大产量达374μmol),前者是后者的2倍.

Methylosinus trichosporium IMV 3011 cell suspensions containing methane monooxygenase were used for methanol biosynthesis from gas mixture of methane and air(O\-2), with EDTA as an inhibitor of methanol dehydrogenase. The optimum reaction conditions were investigated .When cell concentration was about 7.4 mg/mL, and 2 mmol/L EDTA was also treated in the reaction system, the best result was obtained. Batch experiments indicated that sodium formate(20 mmol/L)was superior to sodium succinate(40 mmol/L)with respect to methanol accumulation. The optimum ratio of CH\-4 to air was determined to be 1∶1.7, at which the methane conversion increased to 6.0%. The pressure of gas mixture was also an important factor in methane conversion. In the subsequent continuous reaction , the maximum methanol produced by the cells cultured without Cu2+ medium was 374 μmol to be about two folds of that with Cu2+(190 μmol).