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

Abstract:

[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 16S 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 contained six 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.