小麦秸秆高效腐解菌复合系WSS-1的选育及其菌群分析

Screening and bacterial composition analysis of a complex microbial system WSS-1 for high efficiently decomposition of wheat straws

采用限制性培养技术和温度梯度诱导法,从四川成都平原多年还田的土壤中筛选得到了常温条件下对小麦秸秆具有高效腐解功能的复合菌系WSS-1。该复合菌系在28℃、4d可完全崩解滤纸,进一步的腐解麦秆的试验效果表明:接种WSS-1处理在第6天左右达到CMC酶活最高值,这比目前广泛使用的菌剂A提前了4d;经WSS-1腐解20d后的麦秆断裂拉力值下降了73.66%,降低幅度分别比空白对照和菌剂A处理多出33.7%和8.9%。采用16S rDNA克隆文库法对其细菌组成进行解析,结果表明WSS-1的优势菌群为枯草芽孢杆菌(Bacillus subtilis)、球形芽孢杆菌(Bacillus sphaericus)、粪产碱菌(Alcaligenes faecalis)双酶梭菌(Clostridium bifermentans)和粪肠球菌(Enterococcus faecalis)。

A complex microbial system（CMS） WSS-1 was screened and domesticated from the soils which had a long term straw-returning to fields in Sichuan Province using the restricted cultivation and gradient-temperature induction methods.The WSS-1 could completely decompose filter paper within 4d at 28℃ implying that it had the potential of degrading wheat straw under natural condition.The peak of cellulase production by WSS-1 appeared in the sixth day of the wheat straw decomposition experiments,four days earlier than that treated with the widely used Inoculant A.The tension value at breakpoint of wheat straws treated by WSS-1 could decrease by 73.66% after 20d,which was about 33.7% and 8.9% less than that of the control and the Inoculant A treatment,respectively.The bacterial composition of WSS-1 was analyzed by using 16S rDNA clone library method.The dominant communities of WSS-1 were Bacillus subtilis,Bacillus sphaericus,Alcaligenes faecalis,Clostridium bifermentans and Enterococcus faecium.