Vitamin B_<12> production from a high effective methane fermentation system by CO_2 using acclimated-methogens

在这项研究中，维生素B_<12>的驯化甲烷菌的培养液中分离和定量。在37℃、pH 7的条件下，以H_2/CO_2（80：20 v/v）为底物气体，在停止的试管中培养产甲烷菌。采用<12>Amberlite XDA-2离心管分离维生素B_。与以前的技术相比，使用这种方法可以快速地完成维生素B_的分离<12>。发酵液中维生素B_的含量高达110 mg/L以上<12>。对维生素B_（12）的生产进行了铁钴比的研究，发现铁钴比为0.2-0.6时，维生素B_（12）的产量最高。在以丝瓜为载体的甲烷菌固定化反应器中，HRT为6d时，发酵液中维生素B12的浓度可达37.5mg/L，比常规生产方法提高了110-150倍。本研究表明，CO_2/H_2驯化的产甲烷菌在生长过程中会向胞外培养液中分泌类咕啉，这表明利用产甲烷菌培养系统连续生产胞外类咕啉是可能的。

In this study, vitamin B_<12> was isolated and quantified from the culture broth of acclimated-methanogens. The methanogens were cultivated in the stopped tubes in the batch feed substrate gas (H_2/CO_2, 80 : 20v/v) at pH7 and 37℃. A novel isolation method for vitamin B_<12> was attempted using a centrifuge tube filled with Amberlite XDA-2. Using this method, the separation of vitamin B_<12> can be done quickly compared to previous techniques. A high concentration above 110mg/L of vitamin B_<12> in the culture broth was detected. For vitamin B12 production, the optimum Fe/Co ratio was investigated, we found that with the Fe/Co of 0.2-0.6, the maximum vitamin B12 was obtained. In the case of using methanogens fixed rector with the sponge gourd as carrier at HRT 6 days, we obtained the vitamin B12 concentration in culture broth as 37.5 mg/L (Fig.6), the productivity is 110-150 times higher than conventional production method. This investigation indicates that acclimated-methanogens using CO_2/H_2 excretes corrinoids into the extracellular culture broth during growth, and suggests that the continuous production of extracellular corrinoids using the methanogens cultivation system is possible.