Vc混菌发酵中不同伴生菌伴生能力差异的研究

为考察不同伴生菌伴生的差异与2-酮基-L-古龙酸产量之间的关系,本研究比较了维生素C混菌发酵中2株伴生菌——巨大芽孢杆菌25B和短小芽孢杆菌HJ04的生长特性、胞外蛋白含量,并分别测定了它们与普通生酮基古龙酸杆菌组成的混菌发酵体系的抗氧化能力。结果表明:相对于25B,HJ04生长能力更强,在发酵18和42h,胞外蛋白含量分别为92.2和89.1μg/mL,分别高于前者13.6和4.8μg/mL;与普通生酮基古龙酸杆菌组成的混菌体系的总抗氧化能力在发酵18和42h分别为42.3和57.3U/mL,分别高于前者4.09U/mL(P0.05)和2.73U/mL(P0.05),谷胱甘肽还原酶活力为33.6和59.8U/L,分别高于前者14.5U/L(P0.01)和6.1U/L(P0.05);在Vc混菌发酵中2-KGA的产量提高了10.3mg/mL(P0.05)。研究认为,伴生菌分泌活性蛋白能力及抗氧化能力与混菌体系2-酮基-L-古龙酸产量呈正相关性。

Research on companion distinction of different helper strains in vitamin C mixed-culture fermentation

To explore the correlation between the companion distinction and the 2-KGA yield,the growth characteristics,extracellular protein contents of two helper bacteria of Bacillus megaterium 25B and Bacillus pumilus H J04 which were used in vitamin C mixed-cultures fermentation were compared,and the antioxidant ability of the co-cultured systems composed by Ketogulonicigenium vulgare with them respectively were measured.The results showed that HJ04 had stronger growth ability,the extracellular protein contents of which were 92.2 μg/mL and 89.1 μg/mL respectively after cultivating for 18h and 42h,which were 13.6 μg/mL(P＜0.05)and 4.8 μg/mL(P＜0.05)more than that of 25B.The total antioxidant capacity of the fermentation syste-n made up by the H J04 and Ketogulonicigenium vulgare were 42.3 U/mL and 57.3 U/mL respectively at 18h and 42h,increased by 4.09 U/mL(P＜0.05)and 2.73 U/mL(P＜0.05)compared with that of 25B.The glutathione reductase activities of HJ04 were 33.6 U/L and 59.8 U/L at 18 and 42 h,which were 14.5 U/L(P＜0.01)and 6.1 U/L(P＜0.05)higher than that of 25B.The 2-KGA yield exhibited a rise of 10.3 mg/mL(P＜0.05)in Vc mixed-culture fermentation.The results showed that the active-protein secreting ability and the antioxidant ability of helper bacterium were both positively correlated with the 2-KGA yield in the mixed cultures.