关键词: 胃肠道, NRPS, 儿茶酚类铁载体

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