黄粉虫幼虫肠道不可培养微生物中高效塑料降解新基因开发

研究发现黄粉虫幼虫肠道菌群可以高效分解聚（苯）乙烯塑料，已从中分离出数株塑料降解菌及其对应的降解酶。但这些菌株分解效率低，不能完全解释幼虫肠道的高效塑料降解机制。另一方面肠道菌群中约70%的微生物是不可培养的，宏基因组数据也表明肠道菌含有很多未知功能基因。因此幼虫肠道菌群不可培养微生物中极可能蕴含全新的高效塑料降解基因。本实验室研发出耦联宏转录组与比较宏基因组高效筛选不可培养微生物功能基因的技术，在前期研究中发现黄粉虫幼虫肠道菌群含有多个高效塑料降解的潜在基因。在本项目中，我们将以聚乙烯和聚苯乙烯喂养黄粉虫幼虫，建立塑料降解宏基因组文库和宏转录组学文库，并与喂养白菜叶的对照组进行比较，筛选差异表达的高效塑料降解潜在基因。进而通过异源高效表达技术验证新基因功能，并解析其蛋白质结构来阐述其作用机制。最后在塑料降解菌中高效表达新基因，评估其实际降解能力。为塑料生物降解提供新思路与新基因资源。

It is reported that the intestinal microflora of Tenebrio molitor larvae can degrade polystyrene and other plastics efficiently. Several strains and corresponding enzymes which can degrade plastics have been isolated from the larvae gut microbiome. However, the degradation efficiency is too low to fully explain the plastic degradation mechanism. On the other hand, about 70 % of microbes in gut are not culturable, and the meta-genomic data showed that there are many unknown functional genes in the gut microbiota. Therefore, the non-culturable microorganisms in the larva gut are likely to contain novel genes of high efficient plastics degradation. Our group has developed a technology to screen the functional genes of non-culturable microorganisms by combining meta-transcriptomics with metagenomics. We found that the gut microbiome of Tenebrio molitor larvae contains several potential genes of high-efficiency plastic degradation. In this project, we will feed Tenebrio molitor larvae with polyethylene and polystyrene to establish metagenomics library and meta-transcriptomics library for plastic degradation. They will be compared with the control group fed with cabbage leaves to screen for the differentially expressed genes that are involved in plastic degradation. Then these genes will be expressed in vitro to further clarify their functions. Their protein structures will be studied for plastics degradation mechanism. Finally, the novel genes will be expressed in plastic degradation bacteria to evaluate the actual degradation ability. This project will provided new insights and gene resources for plastic biodegradation field.