Antibacterial producing actinomycetes from Extra Andean Patagonia

•A screening of bioactive actinomycetes from Extra-Andean Patagonia has been performed.•All the strains displaying antibacterial activity belonged to the genus Streptomyces.•Micromonospora CEBF sp. possessed a gen involved in the biosynthesis of ansamycins.•The bioactive metabolites of the most active strain were naphthoquinone antibiotics.

Extra-Andean Patagonia is a vast area in South America with arid soils and vegetation. Desiccation, high salinity and UV radiation of this region are considered positive factors for the isolation of bioactive strains. In the present study, this environment was screened for the first time for antibacterial producing actinomycetes. The isolated strains included members of the genera Streptomyces, Micromonospora, Microbacterium, Nocardia, Dermacoccus, and Dietzia. Among them, four antibacterial producers belonging to the genus Streptomyces were detected and one isolate belonging to the genus Micromonospora harbored the 3-amino 5-hydroxybenzoic acid synthase gene involved in the production of ansamycin-like compounds. The most promising isolate, Streptomyces sp. SUE01, produced pigmented antibiotics of the granaticin class. Since this type of metabolites has been previously isolated from strains growing in desert environments, a relationship between prevailing environmental factors in arid ecosystems and secondary microbial metabolism could be suggested.