Identification of Actinomycete Strain S24 and Its Antagonistic Effects on Aspergillus flavus

Abstract:

Taking Aspergillus flavus as the target, Actinomyces S24 isolated from Mountain Tai soil showed strong antagonistic activity against Aspergillus flavus, Aspergillus niger, Asperegillus alutacells and the other common Aspergillus in food and feed. Based on its morphologic, culture, physiological and biochemical characteristics, chemotaxonomy as well as 16S rRNA sequence analysis, strain S24 was placed within the genus Streptomyces and identified as a similar species with Streptomyces albireticuli, which had a broad inhibition spectrum and its fermentation characteristics were outstanding. The antibacterial substance was stable. Deposed for 100 min at 100°C, there was no obvious influence on its antibacterial activity. Assay using 96-well plate illustrated that the minimum inhibitor concentration (MIC) and minimum antifungal concentration (MFC) of extracellular crude antibacterial extracts against A. flavus were 19.53 μg/mL and 39.06 μg/mL, respectively.

Key words:Aspergillus flavus, Streptomyces albireticuli, Identification, MIC/MFC