为开发秸秆发酵生产有机挥发酸的微生物种子资源和研究材料,以牛粪、猪粪堆肥、玉米地土壤、腐木以及猪粪堆肥和腐木混合物为接种物,通过传代富集培养,选育到发酵水稻秸秆产酸性能相对稳定的5个复合菌群,即FM_c、FM_d、FM_s、FM_w和FM_(d+w).经测试,FM_w具有最高的秸秆降解能力,其秸秆降解率可达46.4%;菌群FM_(d+w)发酵秸秆的总酸和丁酸比产率最高,分别为0.64和0.48g/g;发酵秸秆产乙酸能力以菌群FM_d最为突出,其乙酸比产率为0.35g/g.5个复合菌群均缺乏酸性纤维素酶活性,极大限制了秸秆降解率和产酸率,需要进一步的耐酸驯化和培养条件优化.

To develop genetic resources for microorganisms and to study the volatile fatty acid production by rice straw fermentation, mixed bacterial cultures FM_c, FM_d, FM_s, FM_w and FM_(d+w) were obtained by subculture with cow muck, pig compost soil, rotten wood, and mixture of pig compost soil and rotten wood as inoculums. Among the five mixed cultures, FM_w shows the highest straw degradation rate of 46.4%. The highest specific production rates of the total volatile fatty acid and the total butyric acid from rice straw are reached by the mixed culture FM_(d+w) with a value of 0.64 and 0.48g/g, respectively. The mixed culture FM_d produces more acetic acid from rice straw than others with a specific yield of 0.35g/g. It is found that the five mixed bacterial cultures all lack the acidity glucanase, resulting in a great restriction in the degradation of rice straw and the fatty acid yield. In order to improve the mixed cultures with respect to their fatty acid yield, a domestication to fatty acids and an optimization of cultivation conditions are desirable.