【摘要】 【目的】探讨池塘养殖红螯螯虾(Cherax quadricarinatus)个体大小与其肠道细菌间的关系,为筛选虾类肠道有益菌提供参考依据。【方法】提取池塘养殖红螯螯虾后肠样品的总DNA,采用16S rDNA高通量测序技术对其大个体组(PB组)和小个体组(PS组)肠道微生物进行测序,并进行生物信息学分析。【结果】在红螯螯虾后肠样品中,PB组共检出1211个分类操作单元(OTU),PS组共检出587个OTUs,其中365个OTUs为PB组和PS组肠道微生物共有。Alpha多样性分析结果显示,PB组红螯螯虾肠道微生物多样性的Chao1指数、Ace指数和Shannon指数均极显著高于PS组红螯螯虾(P<0.01)。PB和PS组红螯螯虾肠道微生物排名前十位的优势菌群在门、目和属水平上均相似,但菌群组成和指示物种存在差异,其中,在门水平上,PB组的优势菌门为厚壁菌门,占比42.87%,而PS组的优势菌门为变形菌门,占比59.77%;在目水平上,PB组的优势菌目为梭菌目,占比41.25%,而PS组的优势菌目为肠杆菌目,占比57.01%;在属水平上,PB组的优势菌属为梭菌属,占比30.83%,而PS组的优势菌属为柠檬酸杆菌属,占比36.07%;PB组的指示物种是厚壁菌门和浮霉菌门,而PS组的指示物种是变形菌门。此外,PB组和PS组的菌群代谢功能也存在差异,PB组除影响因子和聚糖生物合成与代谢的丰度显著低于于PS组外(P<0.05,下同),其他代谢(氨基酸代谢、外源生物降解与代谢及萜类化合物和聚酮类化合物代谢等)的丰度均显著高于PS组。【结论】与小个体红螯螯虾相比,大个体红螯螯虾肠道微生物的组成和丰度及其代谢功能明显占优。因此,在相同的养殖环境和饲养方法下,红螯螯虾肠道微生物组成和丰度及其代谢功能是影响红螯螯虾生长性能的内在因素之一。更多还原

【Abstract】 【Objective】The study aimed to explore the relationship between intestinal bacteria and body size of red claw crayfish(Cherax quadricarinatus) cultured in ponds, so as to provide reference basis for beneficial intestinal bacteria of shrimp.【Method】The total DNA of the hindgut samples of red claw crayfish cultured in ponds was extracted. The intestinal microorganisms of large individual group(PB group) and small individual group(PS group) were sequenced by 16 S rDNA high-throughput sequencing technology, and bioinformatics analysis was carried out.【Result】A total of 1211 species level taxonomic operating units(OTUs) were detected in PB group, 587 OTUs in PS group and 365 common OTUs in PB group and PS group. The results of alpha diversity analysis showed that the Chao1 index, Ace index and Shannon index of intestinal microbial diversity of red claw crayfish in PB group were extremely significantly higher than those in PS group(P<0.01). The top ten dominant flora of PB and PS were similar at the phylum, order and genus levels, but there were differences in flora composition and indicator species. At the phylum level, the dominant flora of PB group was Firmicutes, accounting for 42.87%,while the dominant flora of PS group was Proteus, accounting for 59.77%. At the order level, the dominant bacteria in PB group was Clostridium, accounting for 41.25%,while the dominant bacteria in PS group was Enterobacteriaceae, accounting for 57.01%. At the genus level, the dominant bacteria in PB group was Clostridium,accounting for 30.83%,while the dominant bacteria in PS group was Citrobacter,accounting for 36.07%. The indicators of PB group were Firmicutes and Planctomycetes, while the indicators of PS group were Proteus. In addition, there were also differences in the metabolic function of flora between PB group and PS group. Except that the abundance of influencing factors and glycan biosynthesis and metabolism in PB group was significantly lower than that in PS group(P<0.05,the same as below), the abundance of other metabolism(amino acid metabolism, exogenous biodegradation and metabolism, terpene and polyketone metabolism, etc.) in PB group was significantly higher than that in PS group.【Conclusion】Compared with the small red claw crayfish, the composition, abundance and metabolic function of intestinal microorganisms of the large red claw crayfish were significantly superior. Therefore, under the same breeding environment and methods, the intestinal microbial composition, abundance and metabolic function of red claw crayfish were one of the internal factors affecting the growth performance of red claw crayfish.更多还原