蟋蟀后肠纤维素降解细菌的分离与鉴定

近年来,具有农业、能源和环保价值的昆虫微生物种类和基因得到了开发,昆虫肠道微生物展示了其巨大的应用潜力,本研究旨在从蟋蟀后肠分离和鉴定纤维素降解细菌。首先采用羧甲基纤维素钠液体培养基对蟋蟀后肠中的微生物进行富集培养,然后使用羧甲基纤维素钠固体培养基分离和筛选单菌落,再通过16S rRNA测序对纤维素降解细菌进行分子鉴定,最后通过刚果红染色来进一步分析细菌降解纤维素的能力。从蟋蟀后肠中共分离出20株纤维素降解细菌,16S rRNA基因测序结果显示来自肠杆菌属(Enterobacter)9株,不动杆菌属(Acinetobacter)7株,克雷伯氏菌属(Klebsiella)2株,鞘氨醇杆菌属(Sphingobacterium)1株和葡萄球菌属(Staphylococcus)1株。刚果红染色试验结果显示,克雷伯氏菌属两株PDSCDXS_2B和8B,鞘氨醇杆菌属PDSCDXS_7C和不动杆菌属PDSCDXS_12C具有较高的纤维素降解能力。这是首次从蟋蟀后肠分离和筛选出来具有纤维素降解能力的细菌,为昆虫源纤维素降解细菌的研究提供了微生物资源。

Isolation and identification of cellulose-degrading bacteria in the posterior intestine

In recent years, insect microbial species and genes with agricultural, energy and environmental values have been developed, and insect intestinal microorganisms have demonstrated their great potential for application. Our purpose is to isolate and identify cellulose-degrading bacteria from the posterior intestine of crickets. First, carboxymethyl cellulose sodium liquid medium was used to enrich and cultivate microorganisms in the posterior intestine, then carboxymethyl cellulose sodium solid medium was used to separate and screen monophyletic colonies, and the cellulose degradation bacteria were identified by 16S rRNA sequencing. Finally, the ability of bacteria to degrade cellulose was further analyzed by congolese red staining. In our research, 20 cellulose-degrading bacteria were isolated from the posterior intestine of crickets. The sequencing results of the 16S rRNA gene showed that 9 strains were from Enterobacter, 7 from Acinetobacter, 2 from Keleiboshi, 1 from Sphingobacterium and 1 from Staphyloccus. The results of the congo red stain test showed that Keleiboshi has two PDSCDXS_2B and 8B strains, Schwannosin is PDSCDXS_7C, and Acetobacter is PDSCDXS_12C have high cellulose degradation ability. For the first time, we isolated and screened cellulose-degrading bacteria from the posterior intestine of crickets, which provided clues and scientific basis for the study of insect-derived cellulose degradable bacteria.