Antimicrobial activity of Anthostomelloides leucospermi TBT10, an endophytic fungus isolated from Taxus baccata stems against human pathogens
Year: 2020
Type: article
Abstract: The objective of this study is to identify and evaluate the antimicrobial activity of the endophytic fungus TBT10 isolate from Taxus baccata stems.Morphological and molecular identification allowed us to identify this isolate as belonging to the Anthostomelloides leucospermi species.After preliminary screening by agar diffusion method which showed the inhibitory potential of TBT10 against the test bacteria, an optimization of the culture medium, the type of fermentation as well as the extraction solvent was carried out.The Potato Dextrose Agar was the best medium giving the highest production of secondary metabolites with average inhibition zones of 23.25 mm; the liquid culture was the one that gave the best activity (10.13 mm).Regarding the solvent, ethyl acetate extract was the solvent allowing the best extraction of the active molecules with average inhibition zones of 15.88 mm.Ethyl acetate extract was active against all used Gram positive bacteria and the largest inhibition was obtained against Micrococcus luteus (28.5 mm), but Gram negative bacteria were all resistant.MICs were ranged from 0.5625 to 4.50 mg/mL, while the MBCs were between 0.5625 to >4.50 mg/mL and the effect of extract was bactericidal against all bacteria except against Enterococcus faecalis 4 and Enterococcus faecium 1 where it was bacteriostatic.Time kill kinetic of ethyl acetate extract was bactericidal against Enteroccocus faecium 2 after 1 and 24 hours for the MIC×4 (4.50 mg/mL) and MIC×2 (2.25 mg/mL) concentrations respectively.Whereas against Streptococcus pyogenes; the bactericidal effect was observed after 1, 4and 12 hours of contact with MIC×4 (2.25 mg/mL), MIC×2 (1.125 mg/mL) and MIC (0.5625 mg/mL) respectively.TBT10 ethyl acetate extract can be a promising source for production of biologically active molecules.
Author: A Zerroug
Language: English
Subfield: Applied Microbiology and Biotechnology
Field: Immunology and Microbiology
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W3084801550