美洲大蠊成虫肠道可培养细菌多样性研究

Diversity of culturable bacteria isolated from Periplaneta americana adult gut

【目的】了解美洲大蠊成虫肠道可培养细菌的多样性。【方法】运用纯培养法、数值分类和16S r RNA基因序列的系统发育分析对样品中可培养细菌多样性进行研究。【结果】从NA培养基中分离得到54株细菌,根据形态观察和部分生理生化特性,选取32个代表性菌株进行16S r RNA基因序列的系统发育多样性分析。结果表明,数值分类中的代表菌株在82%相似水平上可分为12个表观群;这些分离菌株代表20个物种,属于4个大的系统发育类群(Proteobacteria,Bacteroidetes,Firmicutes,Actinobacteria)的10个科、15个属。多数菌株属于Proteobacteria门(15株,占46.9%)和Bacteroidetes门(10株,占31.3%)。【结论】美洲大蠊成虫肠道内存在较为丰富的细菌多样性。

[Objective] To understand the diversity of culturable bacteria isolated from Periplaneta americana adult gut. [Methods] Bacteria were isolated from the sample by using conventional culture-dependent method and then investigated by using numerical taxonomy and phylogenetic analysis based on 16 S r RNA gene sequences. [Results] Totally 54 bacteria strains were selected on nutrient agar plate. On the basis of morphological, physiological and biochemical characteristics, we selected 32 strains to perform a phylogenetic analysis based on 16 S r RNA gene sequences. The results showed that the strains can be divided into 12 apparent groups on the 82% similarity level by numerical taxonomy; 32 isolates represented 20 species, belonging to 15 genera of 10 families in four phylogenetic groups（Proteobacteria, Bacteroidetes, Firmicutes, and Actinobacteria）. The most abundant and diverse isolates were within the Proteobacteria（15 strains, 46.9%） and the Bacteroidetes（10 strains, 31.3%）. [Conclusion] Overall, the study results presented above demonstrated that there are abundant bacteria diversity in the Periplaneta americana adult gut.