洞庭湖地区6种鱼肠道微生物群落的多样性及组成分析

The Diversity and Composition of Gut Microbiota in Six Species of Fish from the Dongting Lake Area

鱼体中的肠道微生物菌群是一道天然的免疫屏障,能抑制病原微生物的定居和增殖,从而使鱼体免受病害侵袭。洞庭湖是重要鱼类及水生生物的栖息地和基因库,其中鲤形目(Cypriniformes)和鲈形目(Perciformes)种类最多,鲇形目(Siluriformes)种类相对较少。洞庭湖鱼类群落结构及生物多样性已引起广泛关注,但生态系统还是受到了一定程度的破坏,很少有研究将其肠道微生物群的特征作为改善洞庭湖生态系统的潜在因素。为了探测洞庭湖重要鱼类中的微生物群,使用16S rRNA高通量测序表征了鲇形目、鲈形目和鲤形目中6种鱼[黄颡鱼(Pelteobagrus fulvidraco)、鳜鱼(Siniperca chuatsi)、鲫鱼(Carassius auratus)、翘嘴鱼(Culter alburnus)、草鱼(Ctenopharyngodom idella)、鲢鱼(Hypophthalmichthys molitrix)]的肠道细菌群落多样性、组成和潜在的功能。所有鱼类肠道样本中有5种优势菌门,包括厚壁菌门(Fimicutes)、变形杆菌门(Proteobacteria)、梭杆菌门(Fusobacteriota)、放线菌门(Actinobacteriota)和蓝细菌门(Cyanobacteria)。鲤形目和鲈形目鱼类的细菌组成相似,鲇形目中醋酸杆菌属(Cetobacterium)所占比例高,而鲤形目中醋酸杆菌属和气单胞菌属(Aeromonas)所占比例均高。对这6种鱼类肠道微生物群的微生物群落的物种组成和功能进行预测,发现鳜鱼肠道微生物菌群物种的丰富度最高,并且代谢过程较为旺盛,推测这可能与鲈形目的抗病能力和适应能力有关。深入了解鱼类肠道微生物菌群的多样性、组成与潜在功能,不仅可以更好地对微生态制剂使用和其水质管理进行调控,而且对鱼类的健康养殖具有重要的参考价值。

The gut microbiota in fish is a natural immune barrier, which can inhibit the colonization and proliferation of pathogenic microorganisms, so as to protect the fish from diseases. Dongting Lake is a vital fish and aquatic organisms' habitat and gene pool, with more Cypriniformes and Perciformes species present than Siluriformes. The fish community structure and biodiversity in Dongting Lake have attracted extensive attentions, whereas the ecosystem has been damaged to a certain extent. Few studies have taken the characteristics of fish intestinal microbiota as a potential factor to improve the ecosystem of Dongting Lake. In order to detect the microbial community in important fish populations in Dongting Lake. The 16S rRNA high-throughput sequencing was used to characterize the gut bacterial community diversity, composition and potential functions of six fishes including Pelteobagrus fulvidraco, Siniperca chuatsi, Carassius auratus, Culter alburnus, Ctenopharyngodom idella, Hypophthalmichthys molitrix, which are in Siluriformes, Perciformes and Cypriniformes. There were five dominant phyla in all fish gut samples, including Fimicutes, Proteobacteria, Fusobacteriota, Actinobacteriota and Cyanobacteria. The bacterial composition of Cypriniformes and Perciformes was similar. The proportion of Cetobacterium in Siluriformes was high, while the proportion of Cetobacterium and Aeromonas in Cypriniformes were high. The species composition and function of the microbial community of the gut microbiota of the six fish species were predicted. We found that the species richness of the gut microbiota of Siniperca chuatsi was the highest, and the metabolic process was more vigorous. We speculated that this may be related to the disease resistance and adaptability of Perciformes. An in-depth understanding of the diversity, composition and potential functions of fish gut microbiota can not only better regulate the use of probiotics and their water quality management, but also have important reference values for the healthy breeding of fish.