复合菌系CN6生长特性及在沼气发酵中的应用

Growth Characteristics of Complex Strains CN6 and Its Application in Biogas Production

为有效提高纤维素类原料厌氧发酵水解效率,根据不同菌株利用底物差异和产酶互补性,人工构建产纤维素酶复合菌系CN6。通过检测滤纸酶活和纤维素降解率,确定了复合菌系CN6的最适培养温度为30～37℃,最佳培养初始pH值为7.0,菌系CN6遗传性能稳定。复合菌系CN6应用于以牛粪为原料的室内沼气厌氧发酵,发酵0～15 d时,挥发性脂肪酸质量浓度比对照提高26.5%～30.6%,发酵结束时,纤维素降解率比对照提高6.8%,沼气总产量比对照提高18.4%。

In order to improve the hydrolysis efficiency of cellulose materials, an artificial composite system CN6 was constructed by using different substrates and complementary enzymes. By detecting the filter paper enzyme activity and cellulose degradation rate, the optimum fermentation conditions of CN6 were determined as follows ：culture temperature of 30 -37℃ and initial pH value of 7.0. The metabolic process of CN6 was proved to be stable. The complex strains CN6 was applied to biogas fermentation of cow dung as raw material in a laboratory scale reactors. The results showed that the volatile fatty acid （VFA） was increased by 26.5% -30.6% in 0 - 15 d of fermentation. At the end of fermentation, the cellulose degradation rate and cumulative biogas production were increased by 6.8% and 18.4% compared with that of the control.