Study of Periplaneta Americana Microbial Community Structure and Diversity by 16S rRNA High-Throughput Sequencing

Abstract

Objective: The present study probes into the microbial community structure in Periplaneta americana under different breeding conditions, using 16S rRNA high-throughput sequencing technique, in the hope of finding the microbial community structure in Periplaneta americana and their diversity under different breeding conditions.

Methods: In this study, we extract the microbial metagenomic DNA of 5 groups of Periplaneta americana which under different breeding conditions. Using lllumina Miseq sequencing platform, two-terminal sequencing of V3-V4 regions of 16S rRNA were sequenced; diversity of community structure was analyzed using the softwares such as fastqc, QIIME, PyNAST, fasttree and R language.

Results: Shannon index of samples in SG group was lower than that of the other four groups, significantly lower than that of DB group (P<0.05), but not significantly different from other groups. This suggested that the intake of a mixed fodder with high sugar, high fat and high protein by Periplaneta americana can reduce the diversity of microbial communities. Our findings showed that breeding intervention with different fodders may cause differences in the contents of Bacteroidetes, Proteobacteria and Firmicutes in Periplaneta americana. Results showed that long-term intake of lots of sucrose and fat may increase the proportion of Bacteroidetes in Periplaneta americana; and long-term intake of lots of sucrose may reduce the proportion of Proteobacteria in Periplaneta americana; and long-term intake of lots of fat may reduce the proportion of Firmicutes in Periplaneta americana. Two major dominant bacterial genera in all samples were Blattabacterium and Rickettsiella. But different feeding interventions can change the proportions of Blattabacterium and Rickettsiella.

Conclusion: Periplaneta americana has a complex microbial community structure. Different feeding conditions may change the microbial community structure of Periplaneta americana. An important bacterial genus in Periplaneta americana, Blattabacterium is positively correlated with the intake of sucrose- and fat-rich fodder. In the breeding process of Periplaneta americana, adding sucrose and fat to fodder may increase the content and proportion of Blattabacterium in microbial communities.