Ahasan Mohammad Shamim, Waltzek Thomas B, Owens Leigh, Ariel Ellen
College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, 4811, Qld, Australia.
Faculty of Veterinary and Animal Sciences, Hajee Mohammad Danesh Science and Technology University, Dinajpur 5200, Rangpur, Bangladesh.
AIMS Microbiol. 2020 Oct 19;6(4):361-378. doi: 10.3934/microbiol.2020022. eCollection 2020.
are primarily herbivorous long-distance migratory sea turtles that contribute to marine ecosystems. Extensive research has been conducted to restore the populations of green turtles. Little is known about their gut microbiota which plays a vital role in their health. We investigated the mucosa-associated bacterial communities across the gastrointestinal (GI) tract of a total four (3, juvenile and 1, adult) stranded green turtles. Samples taken from four GI regions including oesophagus, stomach, small intestine and large intestine were analysed by high-throughput sequencing targeting hypervariable V1-V3 regions of the bacterial 16S rRNA gene. Bacterial diversity and richness decreased longitudinally along the GI tract from oesophagus to the small intestine of stranded turtles. The large intestine showed a higher bacterial diversity and richness compared to small intestine. The bacterial community of green turtles' GI tract was largely dominated by Firmicutes, Proteobacteria, Actinobacteria, Bacteroidetes and Fusobacteria. Aerobic and facultative anaerobic bacteria prevailed primarily in the oesophagus while anaerobes (, and ) constituted the bulk of large intestinal microbiota. Firmicutes dominated the GI tract except within the small intestine where Proteobacteria prevailed. At the OTU level, six percent of the total OTUs (>1% relative abundance) were common in all GI regions. This is a comprehensive characterisation of bacterial microbiota across the GI tract in green turtles which will provide a reference for future studies on turtle gut microbiome and their metabolism to improve their health and nutrition during rehabilitation.
主要是食草性的长途洄游海龟，对海洋生态系统有重要作用。为恢复绿海龟种群已开展了大量研究。人们对其肠道微生物群了解甚少，而肠道微生物群对它们的健康起着至关重要的作用。我们调查了总共四只（3只幼龟和1只成年龟）搁浅绿海龟胃肠道（GI）各部位的黏膜相关细菌群落。从包括食管、胃、小肠和大肠在内的四个胃肠道区域采集样本，通过针对细菌16S rRNA基因高变V1 - V3区域的高通量测序进行分析。搁浅海龟胃肠道中细菌的多样性和丰富度从食管到小肠沿胃肠道纵向降低。与小肠相比，大肠显示出更高的细菌多样性和丰富度。绿海龟胃肠道的细菌群落主要由厚壁菌门、变形菌门、放线菌门、拟杆菌门和梭杆菌门主导。需氧菌和兼性厌氧菌主要在食管中占优势，而厌氧菌（如、和）构成了大肠微生物群的主体。除小肠中变形菌门占优势外，厚壁菌门在胃肠道中占主导地位。在OTU水平上，所有胃肠道区域中共有6%的总OTU（相对丰度>1%）。这是对绿海龟胃肠道细菌微生物群的全面表征，将为未来关于海龟肠道微生物组及其代谢的研究提供参考，以改善它们在康复过程中的健康和营养状况。
