Antimicrobial activity and amylase production by Rhizophus microsporus strain isolated from germinating maize seed

The study was aimed to determine the antimicrobial activity and enzyme production of Rhizophus microsporus isolated from the maize seed germination experiment. Antifungal and antibacterial activities of the Rhizophus species were studied against Pythium ultinum, Rhizoctonia solani, Fusarium oxysporium, Bacillus sp, Escherichia coli, Pseudomonas and Streptococcus. Rhizophus microspore showed marked antimicrobial activity against Rhizoctonia solani, Bacillus sp and Pseudomonas sp. Bioassays of Rhizophus microsporus on fungal, bacterial, protozoan and nematode were done using the crude extracts of Rhizophus microsporus in methanol and distilled water. Methanol extract exhibited antifungal activity whereas the water extract displayed antibacterial activity. The organism produces volatile and water soluble antibiotics and shows significant inhibition on the formation of sclerotia of Rhizoctonia solani. Antiprotozoan activity was also observed but there was no effect on the motility of nematode. The enzyme amylase which is widely used in the food industry was also produced by this organism. The pH optimum for the amylase enzyme was 8.0 at 40oC and the temperature optimum was 50oC at pH 8.0