鄱阳湖越冬白鹤肠道微生物群落结构及功能预测分析

【目的】分析鄱阳湖越冬白鹤在人工生境中肠道微生物群落组成和代谢功能特征。【方法】利用16S rRNA基因高通量测序技术比较藕田和稻田2种不同人工生境鄱阳湖越冬白鹤肠道微生物群落组成和重建未观察到的状态(phylogenetic investigation of communities by reconstruction of unobserved states, PICRUSt)进行功能预测。【结果】稻田白鹤肠道微生物α多样性(Ace、Chao1、Shannon和Simpson指数)高于藕田白鹤，但未达到显著水平(P>0.05)。基于Binary-Jaccard距离矩阵的β多样性分析发现2种人工生境的白鹤肠道微生物群落结构差异显著(R²=0.312, P<0.05)。不同人工生境鄱阳湖越冬白鹤肠道微生物组成存在差异，藕田白鹤肠道微生物的优势菌属是土孢杆菌属、罗布西亚属和苏黎世杆菌属；稻田白鹤肠道微生物的优势菌属是乳酸杆菌属、里氏杆菌属和球菌属。线性判别分析line discriminant analysis (LDA) effect size, LEfSe]分析发现乳杆菌科、乳酸杆菌属、苏黎世杆菌属等具有较强发酵代谢碳水化合物能力的微生物在2种人工生境下差异显著。PICRUSt功能预测表明鄱阳湖越冬白鹤肠道微生物与新陈代谢、基因信息处理、环境信息处理和人类疾病等功能相关，在level 1水平上，有5类代谢通路具有显著性差异(P<0.001)。【结论】两种人工生境中鄱阳湖越冬白鹤肠道微生物组成和群落特征差异较大，可能是由于同域觅食鸟类的种类、数量以及食物来源的不同。同时，PICRUSt功能预测揭示了不同人工生境中鄱阳湖越冬白鹤肠道微生物功能基因丰度的显著差异，表明白鹤可以通过调整自身肠道微生物组成来适应不同人工生境食物资源的变化带来的挑战。本研究对不同人工生境下白鹤肠道微生物的组成和功能潜力的研究结果可以为鄱阳湖越冬白鹤肠道微生物的研究提供一定依据，对于白鹤的保护和制定管理策略具有一定的参考价值和现实意义。

Gut microbiota structure and function of Siberian crane (Grus leucogeranus) overwintering in Poyang Lake

Objective] To analyze the composition and metabolic characteristics of gut microbiota in Siberian crane (Grus leucogeranus) overwintering in the Poyang Lake. Methods] The 16S rRNA gene high-throughput sequencing was employed to reveal the gut microbiota composition and PICRUSt to predict the function of Siberian crane overwintering in two artificial habitats (lotus field and paddy field) in the Poyang Lake. Results] The alpha diversity indexes (Ace, Chao1, Shannon, and Simpson) showed that the gut microbiota diversity of Siberian crane in the paddy field were higher than those in the lotus field (P>0.05). The beta diversity based on Binary-Jaccard distance matrix revealed significant differences in the gut microbiota structure between the two artificial habitats (R²=0.312, P<0.05). The Siberian crane overwintering in different artificial habitats of the Poyang Lake showed varied gut microbiota composition. Terrisporobacter, Romboutsia, and Turicibacter were dominant genera in the gut of Siberian cranes in the lotus field, while Lactobacillus, Riemerella, and Catellicoccus in the paddy field. Line discriminant analysis effect size (LEfSe) analysis showed that the microorganisms like Lactobacillaceae, Lactobacillus, and Turicibacter with a strong ability to metabolize carbohydrates had significantly different relative abundance between the two artificial habitats. Functional prediction of PICRUSt showed that the intestinal microorganisms were mainly involved in metabolism, gene information processing, environmental information processing, and human diseases. At level 1, there were 5 types of metabolic pathways with significant differences (P<0.001). Conclusion] Different species and number of birds and different food sources of the two artificial habitats resulted in significant differences in gut microbiota composition and characteristics of Siberian cranes overwintering in the Poyang Lake. PICRUSt functional prediction showed that there were significant differences in the abundance of functional genes of gut microbiota in the Siberian cranes overwintering in different artificial habitats, suggesting that Siberian cranes could adapt to the changes of food resources in artificial habitats by adjusting their gut microbiota. We preliminarily studied the composition and function of gut microbiota in the Siberian cranes overwintering in Poyang Lake. The findings underpin the relevant research and provide references for the conservation of overwintering Siberian cranes and the formulation of management measures.