Isolation, characterization, antimicrobial and other bioactivity profiles of three Streptomyces strains isolated from Lake Gerio, Yola, Adamawa State, Nigeria

Actinomycetes are prolific producers of bioactive compounds which can be used to combat microbial infections. Microbial infections have resulted to increase in mortality and morbidity rates world-wide, especially in developing nations. This study was carried out to isolate and identify actinomycetes with potentials of synthesizing bioactive compounds, to produce and partially purify antimicrobial extracts, to characterize bioactive compounds in the extracts, to assess their antibacterial activity and to profile other biological properties of the bioactive compounds synthesized by the actinomycetes. Streptomyces sp. SUI (MT584797), Streptomyces sp. SW72IV (MT584818) and Streptomyces sp. SW72VII (MT584816) were isolated and identified. Ultraviolet–visible spectra absorption ranged between 241 and 251 nm wavelengths showing the polyene or chromone and unsaturation nature of the natural compounds. Infrared (IR) spectra indicated functional groups such as hydroxyl, aliphatic bromo, carbonyls, esters, carboxylic acids and silicon oxy compounds in the compounds produced by the three strains. Gas Chromatography-Mass Spectrum (GC–MS) identified elaidic acid isopropyl ester (32.11%), Octadec-9-enoic acid (17.44%) and 2, 3-dihydroxyl elaidate (10%) to be mostly produced by Streptomyces sp. SUI, Streptomyces sp. SW72IV and Streptomyces sp. SW72VII respectively. The three strains exhibited antimicrobial activity against Bacillus sp. Pseudomonas aeruginosa ATCC 9077, Staphylococcus aureus ATCC 700699, Candida albicans and Aspergilus flavus. The results showed that the three strains of Streptomyces could be sources of antimicrobial bioactive compounds and other secondary metabolites that can be used in the production of pharmaceutical bioactive agents that are effective against pathogens, and production of biological materials that can be used in cosmetics and food industries.