一株促生秸秆降解菌的分离与鉴定

针对秸秆处理不当影响全世界环境污染的问题，筛选多功能秸秆降解菌，旨在得到高效降解秸秆且具有促生作用的微生物菌种。结合纤维素钠-刚果红(CMC-Na)平板筛选，通过16S rRNA基因分析，进行菌株鉴定，得到一株具有纤维素降解效果的菌株XJ-132,经16S rRNA基因鉴定为枯草芽胞杆菌(Bacillus subtilis)。与单独施用秸秆处理相比，加入菌株XJ-132 60 d后，秸秆降解率提高21.0%,且对水稻生长促进作用显著，地上、下部鲜重分别增加17.8%和9.6%。水稻种子喷施菌株XJ-132发酵液，低浓度发酵液对种子萌发具有一定促进作用。结果表明，菌株XJ-132可能通过产吲哚乙酸(IAA)、产铁载体、产氨等多种有益物质，降解秸秆的同时促进水稻生长。筛选具有促生作用的秸秆降解菌能够更好地加速秸秆降解，具有广泛的开发利用前景。

Isolation and Identification of A Growth Promoting Straw Degradable Bacterial Strain

Aiming at the problem that improper treatment of straw affects the environmental pollution all over the world, multifunctional straw degradable bacteria in order to obtain microbial strains that can degrade straw efficiently and promote growth were screened. Combined with cellulose sodium Congo red (CMC Na) plate screening, the strains were identified by 16S rRNA gene analysis. The results showed that a Bacillus strain was identified as Bacillus subtilis with the effect of cellulose degradable. As compared with the treatment of straw alone, after adding XJ-132 strain for 60 days, the straw degradation rate increased by 21.0%, and the growth promotion effect of rice was significant. The fresh weight of aboveground and lower parts increased by 17.8% and 9.6% respectively. After spraying XJ-132 fermentation broth on rice seeds, low concentration bacterial broth has a certain promotion on seed germination. The results showed that strain XJ-132 could degrade straw and promote rice growth by producing indoleacetic acid (IAA), iron producing carrier, ammonia producer and many other beneficial substances. Screening straw degradable bacteria with growth promoting effect can better accelerate straw degradation, and has a broad prospect of development and utilization.