Abstract: In order to screen and identify the facultative anaerobes producing catechol siderophore from adult feces, the facultative anaerobic microorganisms from human gastrointestinal tract were isolated and purified by artificial simulated gastrointestinal tract environment. The positive strains which contained the genes of nonribosomal peptide synthetase (NRPS) in the biosynthesis pathway of catechol siderophore were screened and identified with 16S rRNA sequence. And then the types of products were predicted by the substrate specificity of the NRPS adenin domains, and the abilities of strains to produce catechol siderophore were determined by Rious method. Finally, 8 strains of catechol siderophore-producing bacteria were isolated, which belonged to Bacillus and Escherichia respectively, and the products were bacillibactin  and enterobactin. Among them, Bacillus cereus Gut 16 possessed the strongest ability of producing catechol siderophore (94.75±0.40 μmol/L). The result of this research laid a foundation for the study on the function of the catechol siderophore-producing bacteria in the gastrointestinal nutrition and health.

Key words: gastrointestinal tract, NRPS, catechol siderophore

摘要： 为了对成人粪样中产儿茶酚类铁载体的兼性厌氧微生物进行筛选与鉴定，利用人工模拟胃肠道环境分离、纯化人胃肠道源兼性厌氧微生物，筛选含儿茶酚类铁载体生物合成途径中非核糖体肽合成酶（nonribosomal peptide synthetase，NRPS）基因的阳性菌株，并结合16S rRNA序列鉴定菌株。随后，根据NRPS腺嘌呤结构域的底物特异性预测产物类型，再利用Rioux比色法测定菌株产儿茶酚类铁载体能力。最终分离得到8株人胃肠道源产儿茶酚类铁载体菌株，分属于芽孢杆菌属和埃希氏菌属，其产物分别为芽孢杆菌素和肠杆菌素，其中Bacillus cereus Gut 16产儿茶酚类铁载体的能力最强（94.75±0.40 μmol/L）。研究结果为儿茶酚类铁载体产生菌在胃肠道营养与健康中作用的相关研究奠定了基础。

关键词: 胃肠道, NRPS, 儿茶酚类铁载体