Abstract: 【Aim】 This study aims to determine the composition of intestinal bacteria in Proisotoma ananevae and to screen the cellulolytic bacteria. 【Methods】 The intestinal bacteria in P. ananevae adults were isolated and identified with traditional culturing method in combination with 16S rRNA sequencing. The cellulolytic bacteria were screened with carboxymethyl cellulose (CMC) plate media, and the cellulase activity was measured by 3,5-dinitrosalicylic acid (DNS) method under different pH conditions (pH 5.0-9.0). 【Results】 We isolated twenty bacterial strains from the intestinal tract of P. ananevae adults, which belong to 10 genera of three major phyla Firmicutes, Proteobacteria and Acinobacteria, i.e., Staphylococcus, Bacillus, Terribacillus, Advenella, Lysinibacillus, Arthrobacter, Enterobacter, Glutamicibacter, Leucobacter and Acinetobacter, and one unidentified bacterium. Among them, 10 strains were cellulolytic bacteria belonging to 6 genera of Firmicutes and Acinobacteria, i.e., Leucobacter, Bacillus, Terribacillus, Lysinibacillus, Arthrobacter and Glutamicibacter. The cellulase activities in all the cellulolytic strains were relatively higher under pH 7.0-9.0 and reached the maximum under pH 8.0. 【Conclusion】 The results suggest that the bacteria in the intestinal tract of P. ananevae adults have complex structure. The presence of a large number of cellulolytic strains in P. ananevae, the disintegrator in ecosystem, not only helps springtails use macromolecules to meet their own nutrition requirements, but also has important application value especially in feed production and industrial application.

Key words: Proisotoma ananevae, intestinal bacteria, 16S rDNA sequencing, cellulolytic bacteria, enzyme activity