Bao Hongxu, Zhang Xin, Su Hongzhi, Li Liangyu, Lv Zhizhong, Zhang Xinyue
School of Environmental Science, Liaoning University Shenyang 110036 China
Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences Shenyang 110016 China.
RSC Adv. 2019 Mar 19;9(16):9030-9040. doi: 10.1039/c9ra00165d. eCollection 2019 Mar 15.
Based on the principle of reciprocal symbiosis and co-metabolism of mixed culture microorganisms, a group of high-efficiency maize straw-degrading hydrogen-producing complex bacteria X9 + B2 was developed by a strain matching optimization experiment. Systematic research and optimization experiments were carried out on the mechanism of the main controlling factors affecting the hydrogen production of the complex bacteria. The results showed that the optimum conditions for the acid blasting pre-treatment of maize straw as a substrate were as follows: when the inoculation amount was 6% and the inoculum ratio was 1 : 1, at which point, we needed to simultaneously inoculate, the initial pH was 6, the substrate concentration was 12 g L, and the culture time was 40 h. The complex bacteria adopted the variable temperature and speed regulation hydrogen production operational mode; after the initial temperature of 37 °C for 8 hours, the temperature was gradually increased to 40 °C for 3 hours. The initial shaker speed was 90 rpm for 20 hours, and the speed was gradually increased to 130 rpm. The maximum hydrogen production rate obtained by the complex bacteria under these conditions was 12.6 mmol g, which was 1.6 times that of the single strain X9 with a maximum hydrogen production rate of 5.7 mmol g. Through continuous subculturing and the 10, 20, 40, 60, 80, 100 and 120 generation fermentation hydrogen production stability test analysis, no significant difference was observed between generations; the maximum difference was not more than 5%, indicating better functional properties and stability.
基于混合培养微生物互惠共生和共代谢原理，通过菌株匹配优化实验，构建了一组高效降解玉米秸秆产氢复合菌系X9 + B2。对影响复合菌产氢的主要控制因素作用机制进行了系统研究和优化实验。结果表明，以玉米秸秆为底物进行酸爆预处理的最佳条件为：接种量6%、接种比例1∶1，此条件下需同时接种，初始pH值为6，底物浓度为12 g/L，培养时间为40 h。复合菌采用变温变速调控产氢运行模式；初始温度37℃培养8 h后，逐渐升温至40℃培养3 h。初始摇床转速90 rpm培养20 h后，转速逐渐升至130 rpm。在此条件下复合菌系获得的最大产氢速率为12.6 mmol/g，是最大产氢速率为5.7 mmol/g的单菌株X9的1.6倍。通过连续传代及对第10、20、40、60、80、100和120代发酵产氢稳定性测试分析，各代间未观察到显著差异；最大差异不超过5%，表明具有较好的功能特性和稳定性。
