湿地土壤中纤维素降解菌的分离筛选研究

为了得到更高效地分解堆肥中纤维素成分的细菌,以羧甲基纤维素钠为碳源,从土壤样品中初步分离能降解纤维素的细菌,对其进行革兰染色和16S rDNA序列分析;通过纤维素刚果红水解圈测定、滤纸条降解试验和纤维素酶活力测定对已分离保存的菌株做进一步筛选。结果表明,以羧甲基纤维素钠为碳源,初步分离得到土壤中纤维素降解菌41株,进一步筛选到具有刚果红水解圈菌株6株,6株菌中可以更好地降解滤纸条的有3株,分别为XQ-8、XQ-10和XQ-11,经16S rDNA鉴定该3株菌中有2株为吉氏纤维素菌（Cellulomonas gilvus）,1株为恶臭假单胞菌（Pseudomonas putida）,且该3株菌的纤维素酶活力分别为（28.95±1.48）、（54.70±1.56）、（58.85±3.75）U/mL。该研究从土壤中筛选得到了3株具有较高纤维素酶活力的细菌,可以作为有效降解纤维素的潜力菌株进行粪污堆肥发酵剂的研制。

Isolation and Screening of Cellulose-degrading Bacteria from Wetland Soil

In order to screen the bacteria that can more effectively degrade the cellulose components in composts, the bacterial strains with certain cellulose-decomposing ability were isolated from the soil samples using sodium carboxymethylcellulose as carbon source. Subsequently, the isolates were phenotypically identified with Gram′s staining method and were molecularly confirmed by 16s rDNA sequence analysis. Further screening test was carried out among the obtained isolates by using cellulose-Congo red medium, filter paper degradation test and cellulase activity determination test. The results showed that a total of 41 strains of cellulose-degrading bacteria were isolated from soil samples, and 6 of them exhibited better hydrolysis capacity in cellulose-Congo red medium. Among the 6 isolates, 3 strains designated as XQ-8,XQ-10 and XQ-11 had better performance in filter paper degradation test. The 16s rDNA-based identification revealed that 2 of them were Cellulomonas gilvus and the remaining one was Pseudomonas putida. The cellulase activity of these 3 strains were determined as （28.95±1.48） U/mL, （54.70±1.56） U/mL and （58.85±3.75） U/mL, respectively. In conclusion, this study obtained 3 strains of cellulose-degrading bacteria with higher cellulase activity from wetland soil, which may provide potential high-effective cellulose-degrading bacterial strains for the development of manure composting starter.