造纸废液氧化塘纤维素酶产生菌群的分析与产酶菌株的筛选

Community composition and screening of cellulase-producing bacteria in a papermaking wastewater oxidation pond

【目的】解析造纸废液氧化塘中产纤维素酶微生物的群体组成和结构;筛选并获得一批纤维素酶产生菌,丰富菌株资源,并为纤维素酶的工业应用和环境污染的生物处理奠定基础。【方法】基于16S rRNA基因序列信息,系统考察了造纸废液氧化塘环境中产纤维素酶细菌的群体组成和结构,并通过测定纤维素酶在不同pH条件下酶活变化考察所产纤维素酶的特性。【结果】造纸废液氧化塘中产纤维素酶微生物具有丰富的多样性。在分类上分属于Firmicutes、Actinobacteria、Alpha-proteobacteria和Gamma-proteobacteria 4个门(亚门)15种。来自泥液混合样和黑液排污口泥样的产纤维素酶细菌群体多样性最为丰富,由6-7个种的细菌组成;而来自强碱性的黑液下层样品中微生物的多样性则较为贫乏,主要由来自Bacillus类细菌组成。分离菌株除酸性纤维素酶产生菌外,碱性纤维素酶和中性纤维素酶产生菌也较为丰富,且其分布与样品来源有紧密的关系。【结论】对造纸废液氧化塘产纤维素酶微生物群体组成和结构的研究,不仅有利于对新菌株资源的挖掘,也可为特殊环境的微生物学研究提供参考。

[Objective] To study the community composition of cellulase-producing bacteria in papermaking wastewater oxidation pond, and to screen cellulase-producing bacteria to enrich the microorganism resources for industrial application and biological treatment of environmental pollution. [Methods] The community compositions and the phylogeny of cellulolytic bacteria in the papermaking wastewater oxidation pond were studied on the sequences of the 16 S rRNA genes.Cellulase secreted by these bacteria were characterized under different pH value. [Results] The cellulolytic bacteria in the papermaking wastewater samples were diversified. They could be phylogenetically classified into Firmicutes, Actinobacteria, Alpha-proteobacteria and Gamma-proteobacteria and further divided into 15 species at a higher resolution. The communities in liquor-mud mixture and sludge outlet of black liquor have the most abundant diversity, and containedsix to seven species. These rich diversities maybe owing to the marginal effect and mild pH condition of the environments. Due to the stringent pH condition, the microbial diversity of the lower layer of pond was relatively poor, and Bacillus was the dominant group. The types of cellulase produced by the bacteria in oxidation pond not only contained acidic cellulase, but also contained abundant alkaline cellulases and neutral cellulases. [Conclusion] A number of excellent cellulase-producing bacteria were screened with potential applications.