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oai:riuma.uma.es:10630/340062026-02-03T10:55:07Zcom_10630_2254col_10630_37953

00925njm 22002777a 4500 dc Molina-Santiago, Carlos author Udaondo, Zulema author Daddaoua, Abdelali author Roca, Amalia author Martín, Jesús author Pérez-Victoria, Ignacio author Reyes, Fernando author Ramos, Juan Luis author 2015-01-08 Pseudomonas putida DOT-T1E-18 is a strain deficient in the major antibiotic efflux pump (TtgABC) that exhibits an overall increased susceptibility to a wide range of drugs when compared with the wild-type strain. We used this strain as a platform to search for microbes able to produce antibiotics that inhibit growth. A collection of 2400 isolates from soil, sediments and water was generated and a drop assay developed to identify, via growth inhibition halos, strains that prevent the growth of DOT-T1E-18 on solid Luria-Bertani plates. In this study, 35 different isolates that produced known and unknown antibiotics were identified. The most potent inhibitor of DOT-T1E-18 growth was an isolate named 250J that, through multi-locus sequence analysis, was identified as a Pseudomonas sp. strain. Culture supernatants of 250J contain four different xantholysins that prevent growth of Gram-positive bacteria, Gram-negative and fungi. Two of the xantholysins were produced in higher concentrations and purified. Xantholysin A was effective against Bacillus, Lysinibacillus and Rhodococcus strains, and the effect against these microbes was enhanced when used in combination with other antibiotics such as ampicillin, gentamicin and kanamycin. Xantholysin C was also efficient against Gram-positive bacteria and showed an interesting antimicrobial effect against Pseudomonas strains, and a synergistic inhibitory effect with ampicillin, chloramphenicol and gentamicin. Molina-Santiago C, Udaondo Z, Daddaoua A, Roca A, Martín J, Pérez-Victoria I, Reyes F, Ramos JL. Efflux pump-deficient mutants as a platform to search for microbes that produce antibiotics. Microb Biotechnol. 2015 Jul;8(4):716-25. doi: 10.1111/1751-7915.12295. Epub 2015 Jun 8. PMID: 26059350; PMCID: PMC4476826. doi:10.1111/1751-7915.12295 https://hdl.handle.net/10630/34006 10.1111/1751-7915.12295 Pseoudomonas Antibióticos Efflux pump-deficient mutants as a platform to search for microbes that produce antibiotics