青海农用沼气池微生物群落结构及差异基因功能分析

Microbial Community Structure and Differential Gene Function Analysis of Rural Household Biogas Digesters in Qinghai Province

文章以产气性能不同的青海农用沼气池为研究对象,利用宏转录组学技术分析了温度最高和最低时期污泥样品的微生物组成、差异基因表达及代谢过程。物种注释表明4个样品中最优势的种类均为细菌,且较优势类群有假单胞菌属(Pseudomonas)、硫单胞菌属(Sulfurimonas)、海螺菌属(Marinospirillum)和拟杆菌门未分类属(norankp_Bacteroidetes)。差异基因的筛选结果表明产气性能不同的沼气池样品具有更多的差异基因。通过KEGG pathway富集分析发现,产气好样品的代谢通路表达量更大,且对碳水化合物和氨基酸的利用率及产能更高。同时,参与氨基酸代谢、核苷酸代谢、碳水化合物代谢以及能量代谢等过程的差异表达基因显著富集,说明这几种代谢途径在青海农用沼气池微生物的代谢过程中占据重要地位。4个样品两两比较可知,产气性能不同的比较组差异基因注释到的代谢通路更多,且微生物及其代谢的差异更大。

This paper repoerted on an investigation project about household biogas digesters of rural areas conducted in Qinghai Province. Four sludge samples of the digesters were taken, the temperature change(highest and lowest) in different seasons was taken into consideration, and the analyses of four sludge samples were done by means of the metatranscriptomics technology, probing into microbial compositions, differential gene expression and metabolic processes. The species annotation indicated that the most dominant species in those samples were bacteria, the lesser dominant being the groups—Pseudomonas,Sulfurimonas, Marinospirillum and norank;acteroidetes. According to the differential gene screening, samples of those biogas digesters with different gas production performances had more diverse genes. It was found by KEGG pathway enrichment analysis that the samples of better gas-production had higher metabolic pathway expression level, as well as greater utilization rates and productivity of carbohydrates and amino acids. At the same time, the differently expressed genes involved in amino acid metabolism, nucleotide metabolism, carbohydrate metabolism and energy metabolism were significantly enriched, which suggested that the metabolic pathways of the rural household digesters in Qinghai Province had critical position in the metabolic process of microorganisms. Paired comparison of the four samples showed that the comparison group with different gas production performances had more metabolic pathways annotated by various genes, and the differences in microorganisms and their metabolism were significant.