Polyunsaturated fatty acid-producing marine thraustochytrids:A potential source for antimicrobials

Objective:To evaluate the antimicrobial activity of marine thraustochytrids extracted from different solvents.Methods:Crude extracts were derived from marine thraustochytrids,isolated from decaying mangrove leaf litter.The extracts were tested for antibacterial activity by using agar disc diffusion method against 10 clinical bacterial strains.The extracts were also analysed for presence of functional chemical groups by using Fourier transform infrared spectroscopy.Results:Thraustochytrid extracts exhibited potent antibacterial activity against both Gramnegative and-positive bacteria.The antibacterial activity was observed prominently in butanol extract,followed by petroleum ether,methanol and chloroform extracts.The antibacterial activity was maximum[(21.33±1.52)mm]against Staphylococcus aureus and minimum[(7.00±2.00)]mm against Klebsiella pneumonia and Salmonella typhi.Conclusions:Thraustochytrids isolated from decaying mangrove leaf litter are potential sources of antibacterial compounds against clinical pathogens,which are called for further investigation of thraustochytrids as natural antibiotics.