Survey of Fusarium Species in an Arid Environment of Bahrain. V. Antimicrobial Activity of Some Local and International Fusarium Species

Abstract

Antimicrobial activity of extracellular secondary metabolites of local and international Fusarium species were screened by an agar disc diffusion technique against selected groups of Gram-negative and Gram-positive bacteria, yeasts and filamentous fungi. A total of 37 Fusarium isolates were recovered from Bahrain, using soil dilution and soil washing techniques, and plated onto Komada selective media. Of the recovered isolates, two species, F. dimerum and F. scirpi var. compactum were recorded for the first time from an arid environment of Bahrain. Inhibitory effects were restricted to 21 local and 28 international Fusarium species obtained from a culture collection. Data from repeated experiments revealed consistent, uniform and stable activity among the tested organisms. Fungi were more sensitive to extracts from local Fusaria, followed by Gram-positive bacteria, when compared to standard pure antibiotic discs. Among international Fusarium species, the highest inhibitory activity was reported against Gram-positive bacteria, whereas reduced, but similar effects, were shown against filamentous fungi and Gram-negative bacteria. Production of metabolites was quantitatively more prominent in local Fusarium species than in international ones.