海水混养池塘虾蛤肠道与养殖环境的微生物多样性

【背景】海水混养池塘环境微生物以及动物肠道微生物的群落结构已有研究,但对混养环境中多品种动物肠道与环境微生物群落的关系尚未见报道。【目的】研究海水虾蛤混养环境中微生物多样性以及与养殖动物健康之间的关系。【方法】采用Illumina高通量测序技术测定冬季莆田市北江养殖区2个混养池塘中水体、底泥以及虾蛤肠道的菌群结构。【结果】同一池塘水体与底泥之间、不同池塘水体或底泥之间的微生物结构存在一定的差异;同一养殖区2个混养池塘虾与蛤肠道微生物结构之间具有极高的相似性,与养殖环境存在显著的差异。微生物多样性和丰富度差异很大,表现出底泥水体肠道;虾蛤肠道微生物以厚壁细菌和γ-变形细菌为主;池塘水体以放线菌、α-变形细菌以及拟杆菌为主,底泥以γ-变形细菌和δ-变形细菌为主。养殖动物肠道微生物主要优势种为乳球菌属和假单胞菌属,池塘环境内存在较高丰度的黄杆菌类潜在致病菌,而在虾和蛤的肠道中基本未检出。2个池塘底泥硫还原细菌含量较高,增加了底质产生硫化氢等有害物质的风险。【结论】比较混养池塘中水体、底泥以及虾蛤肠道三者之间微生物群落结构的差异,揭示虾、贝混养模式微生物与养殖环境的关系,为池塘养殖虾、贝疾病防治和混养结构的优化提供参考。

Microbial community diversity in seawater polyculture pond of shrimp and clam

Background] Although microbial community in polyculture environment and animal intestines have been reported in previous studies, relationship of microbial community between intestinal microflora and polyculture environment needs to be deeply studied. Objective] To study microbial communities of shrimp and clam intestine associated with polyculture environment. Methods] Illumina sequencing was used to identify shift of taxonomic diversity among samples collected from two polyculture ponds in Putian. Results] Bacterial community of shrimp intestine had very high similarity with clam intestine collected from two different polyculture pond. Shannon and Chao1 estimator supported the diversity results and suggested that the bacterial community in pond sediments was richer than those in pond water and animal intestine. Furthermore, bacterial community of animal intestines was dominated by Firmicute and Gammaproteobacteria, and culture water was dominated by Actinobacteria, Alphaproteobacteria and Bacteroidete, as well as by Gammaproteobacteria and Deltaproteobacteria in the underlying sediment. High abundance of potential probiotics, such as Lactococcus and Pseudomonas, was detected in animal intestine. Conditional pathogenic bacteria (such as Flavobacterium) had high abundance in polyculture environment, whereas little pathogenic bacteria were detected in animal intestine. Finally, high abundances of sulfate-reducing bacteria were found in the pond sediments, which may cause serious harm to aquaculture environment through producing hydrogen sulfide. Conclusion] This study explores the significant difference of microbial community between polyculture environment and animal intestines and revealed the effect of polyculture environment on intestinal microflora. This study will provide reference for the optimization of polyculture structure and the diseases prevention of aquaculture animals.