高效纤维素分解菌的分离鉴定及堆肥效果研究

采用CMC-Na平板法和刚果红染色法从自然发酵的牛粪中分离获得高效纤维素分解菌,通过形态学观察、生化试验及16S rDNA分子生物学对菌株进行鉴定,采用单因素法确定菌株的最佳培养条件,最后接种牛粪进行堆肥发酵观测其效果。结果表明:获得的菌株Y2鉴定为枯草芽孢杆菌;经产酶条件优化后,菌株Y2的滤纸酶活力(FPA)为15.83 u·mL~(-1),羧甲基纤维素酶活力(CMCA)高达100.81 U·mL~(-1),分别是优化前的1.3、2.76倍。堆肥试验结果表明:接种Y2组和EM菌剂组均在第3 d进入高温期(50℃),且高温期分别维持了9 d和8 d,接种Y2组纤维素降解率达到42%,而EM菌剂组为35%,接种无菌水组只有10.5%。菌株Y2在堆肥发酵方面具有较大的应用潜力。

Isolation and identification of a cellulolytic bacterium and its composting application

Composting is a good approach to utilizing agricultural organic wastes. Supplying microorganisms could shorten composting period and improve compost quality. In this study, a cellulose-decomposing strain was isolated from natural composting manure by using congo red staining and CMC-Na plate method. The strain was identified according to morphological observation, biochemical testing and 16S rDNA gene sequence. The optimal fermentation conditions were also determined by using single factor and orthogonal experiment. Finally, the isolate was inoculated into cattle mature to test its effect. The strain Y2 was identified as Bacillus subtilis; Its FPA and CMCA were 15.83 U·mL^-1 and 100.81 U·mL^-1, 1.3 times and 2.76 times higher than originals, respectively. Compost inoculated with Y2 and EM microbial agents reached high temperature after 3 d, with high temperature maintained for 9 d and 8 d, respectively. The degradation rate of cellulose was 42% for Y2 group, while it was 35% for EM microbial agent and 10.5% for sterile water. Therefore, strain Y2 has a great potential to be applied to composting fermentation.