Abstract
Background: Catechol siderophores, which are widespread in the human gastrointestinal tract (GIT) and play important roles in maintaining iron-nutrition balance between microorganisms and host, are small molecules with a high affinity for ferric iron and are assembled by nonribosomal peptide synthetases (NRPS). In this study, we select strains encoding NRPS A domain gene from feces of a health female adult, predict its products type, and check it out in vitro . Results: Firstly, eight bacteria were determined encoding NRPS A domain gene, and then two kind of catechol siderophores, Bacillibactin and Enterobactin, were predicted according to NRPS A domain substrate specificity. Secondly, Bacillibactin and Enterobactin were checked out in cultured medium aerobic incubated with selected strains of E. Coli, Bacillus sp. and B. Cereus. For the yield of catechol siderophores, B. cereus Gut 16 secreted highest yield of Bacillibactin and E. coli Gut 07 produce highest yield of Enterobactin. Conclusion: By presence determination and activity prediction of NRPS A domain, two siderophores, Bacillibactin and Enterobactin, were checked out finally being secreted by selected strains cultured in a aerobic medium. Further research on the potential probiotic property is necessary to affirm the application in biological industry, as well as to elucidate their mechanism in human gut. Keywords : Catechol siderophores, Enterobactin, Bacillibactin, NRPS A domain, Feces, Probiotics