不同年龄大熊猫肠道菌群及其酶活特征分析

旨在探究年龄对大熊猫个体肠道微生态的影响。本研究采集大熊猫（Ailuropoda melanoleuca）（J₁（亚成年大熊猫个体）、J₂（成年大熊猫个体）、J₃（老年大熊猫个体））的新鲜粪便，基于16S rRNA基因技术，测定不同年龄的大熊猫个体肠道细菌组成，分析其物理和化学特征及酶活特异性，利用冗余分析（redundant analysis，RDA）分析大熊猫肠道微生物菌群丰度与其环境因子之间的关系。结果表明：在门水平上，变形菌门的相对丰度随着年龄的增加而升高，厚壁菌门的相对丰度随着年龄的增加而降低；在属水平上，链球菌属的相对丰度随着年龄的增加而降低；淀粉酶和纤维素酶的酶活力在J₂肠道最高，淀粉酶活力在J₃肠道最低，纤维素酶活力在J₁肠道最低，蛋白酶活力在J₁肠道最高，在J₃肠道最低；厚壁菌门和拟杆菌门的相对丰度均与淀粉酶活力和还原糖含量呈正相关，变形菌门的相对丰度与还原糖含量和氨基酸含量呈负相关。研究表明，不同年龄大熊猫个体的肠道微生物菌群的表现特征不同，其肠道细菌优势菌的相对丰度与其消化酶等环境因子存在相关性；建议需对亚成年大熊猫加强饮食和生活环境管理，并可以通过添加益生菌等方式加强对老年大熊猫肠道健康的管理。

Research on Microbiota and Enzyme Activity Characteristics in the Feces of Giant Pandas of Different Ages

This study was conducted to investigate the effect of different ages on intestinal micro-ecology of the giant pandas. Fresh feces of the giant pandas (Ailuropoda melanoleuca) under different agesJ₁ (sub-adult giant panda), J₂ (adult giant panda) and J₃ (old giant panda)] were collected. The bacterial composition in the feces was determined by 16S rRNA gene technology. The physical and chemical characteristics as well as activities of specific enzymes were analyzed. The correlation between the fecal microbiota and the fecal environmental factors of the giant pandas were analyzed by redundant analysis (RDA). The results showed that the relative abundance of the Proteobacteria increased with age at the phylum level. The relative abundance of Firmicutes decreased with age. The relative abundance of Streptococcus decreased with age at the genus level. The activity of amylase and cellulose were the highest in the feces of the J₂, the activity of amylase was the lowest in the feces of J₃, and the activity of cellulase was the lowest in the feces of J₁. The activity of protease was the highest in the feces of J₁, and the lowest in the feces of J₃. The relative abundance of Firmicutes and Bacteroidetes were positively correlated with amylase activity and reducing sugar content. The relative abundance of Proteobacteria was negatively correlated with reducing sugar content and amino acid content. The study showed that the fecal microbial of the giant pandas of different ages exhibited different characteristics. The relative abundance of dominant bacteria in the feces of the giant pandas was correlated with environmental factors such as fecal digestive enzymes. It is suggested that the diet and living environment of the sub-adult giant pandas should be improved, and probiotics can be added to the diet in order to improve gut health of the old giant pandas.