Tuna Condensate Waste with Molasses as a Renewable Substrate for Antifungal Compounds by Streptomyces philanthi RL-1-178 Against Aflatoxingenic B1 (AFB1) Aspergillus flavus

This study aims to utilize tuna condensate as a renewable resource for production of antifungal compounds by Streptomyces philanthi RL-1-178 against aflatoxingenic B-1 (AFB(1)) Aspergillus flavus. Among ten isolates of A. flavus tested, the strain PSRDC-4 was the most toxigenic strain (1432 ppb of AFB(1)) and aggressive to S. philanthi (85.9% inhibition). The effective dose (100% inhibition) of the culture filtrate RL-1-178 was at 10.0% (v/v) with 1 h exposure time. The antifungal compounds, identified by GC-MS analysis, were consisted of 105 components with 2,4-imidazolidinedione (31.2%) followed by acetic acid (25.27%) was the most abundant. The optimum condition for growth and production of antifungal compounds from S. philanthi RL-1-178 was as following; tuna condensate of 15,000 mg L-1 COD, the initial pH at 7.0, incubation temperature at 30 degrees C and supplemented with 8 g L-1 of molasses. Therefore, tuna condensate exhibited a high potential to be utilized as an alternative medium for antifungal production by S. philanthi RL-1-178.