| The M. voltae BIOMA 5671 provided by Biogas Research Institute of the Ministry of Agriculture is belong to Methanococcus, ceils of M. voltae are Gram negative. The strain grows best at pH values near 6.7-7.4 , the optimal growth temperature is 35～40℃,and it is capable of using H2/CO2 or formate as substrates for CH4 formation. The experiment used original substrates CO to acclimate M. voltae, and concerned the research on using M. voltae converting CO to CH4 and its metabolic rout.The primary research on using M. voltae converting CO to CH4 indicates that M. voltae could utilize H2/CO or pure CO to produce CH4, Ni2+/Fe2+ improved the average speed of CH4 output and the CH4 total output. The average speed of CH4 output with H2/ CO was 1.32μmol/mg (fresh cell weight), It is almost seven times that of with pure CO, which was only 0. 19μmol/mg (fresh cell weight). After120 hours, the number of bacterium in medium with H2/CO arrived 1.4×107 per ml, and in medium with pure CO was 9.5×106 per ml.Besides, Selenium and calcium pantothenate could promote the growth of M. voltae with CO; and the optimum CO concentration of growth resulted to be 25% (V/V). In this CO concentration, the average speed of CH4 output of using H2/CO was 1.98μmol/mg (fresh cell weight), hour, the number of bacterium arrived 1.4×107 per ml after120 hours, as well as the average speed of CH4 output of using pure CO was 0.42μmol/mg (fresh cell weight), hour, the bacterium quantity was 9.5×106 per ml. When the concentration of CO was higher than 25% (V/V), the methane production was inhibited when using H2/CO and pure CO, however, the inhibition of using H2/CO is obviously lower than that of using pure CO.CO2 and H2were detected in medium with pure CO, however, in medium with H2/CO, no CO2 was detected during methane formation. More over, it resulted that M. voltae could utilize both H2/CO and pure CO to produce formate .and it was capable of synthesizing the acetate in the medium without acetate...
|
PDF Full Text Request