Screening of Fungi from Disposed Maize Cobs for Amylase Production

Background of Study: Microorganisms in particular have been regarded as treasure of useful enzymes. There is a great variation between various genera as to their ability to produce a specific enzyme for the production of particular enzymes varies with the particular medium and pH. Place and Duration of Study: The study was conducted at the Department of Microbiology Laboratory, Abubakar Tafawa Balewa University, ATBU, Bauchi Nigeria, from November, 2020 to October, 2021. Aim: This study was aimed to isolates fungi from disposed maize cobs and evaluates its potentials to produce amylase. Methods: Twelve samples each was collected from three different areas; market place, farmland and residential areas in Bauchi metropolis, (a total of 36 samples in all) using precise aseptic techniques. Each sample was collected using clean polythene bag, transported to the lab and aseptically blended. One gram of each sample was aseptically weighed and placed in a test tube containing sterile water; it was then allowed to stand for 30 minutes. One ml of the stock solution was serially diluted and 10ml dilution of each sample was plated on Potato Dextrose Agar (PDA) media. The plate was incubated at 25°C within a period of three, five and seven days during which they were monitored and examined, to isolate the required fungi species. The isolates were tested for amylolytic activity using 1% iodine and screen for amylase production by pre-treatment and solid state fermentation, then α-amylase activity finally determined. Results: Amylase-producing fungi were isolated from maize cobs collected from residence, market and farm areas in Bauchi metropolis. The ability of ten (10) fungal isolates recovered, (Mucor racemosus, Aspergillus niger Penicillium chrysogenum, Rhizopus oryzae, Microsporum sp, Trichoderma sp, Nocardia sp, Monilla sp, Fusarium sp and Chaetomum sp) to degrade starch was determined. Three (3) of the fungal isolates Aspergillus niger Penicillium chrysogenum, Rhizopus oryzae, had the highest frequency of (20%) each. Four (4) of the fungal isolates (Mucor racemosus, Aspergillus niger, Penicillium chrysogenum and Rhizopus oryzae) showed zone of clearance on starch agar medium, the fungi isolates were selected and subjected to various temperatures, incubation time and pH ranges for amylase production. The results showed that Penicillium chrysogenum and Rhizopus oryzae have maximum amylase activity at temperature 35°C, incubation time 96hrs (4days), pH 5.5 and temperature 30°C,incubation time 96hrs(4days) and pH 5.0 respectively. Penicillium chrysogenum produced 46.3μ/ml, and Rhizopus oryzae, produced 30.8μ/ml of amylase. Conclusion: The results of this work proved Penicillium chrysogenum to be the best producer of amylase compared to Rhizopus oryzae. Isolation of amylase producing fungi from maize cobs from residence, market and farm areas will help in the bioremediation of environment, which could have caused environmental pollution. It is recommended that Penicillium chrysogenum and Rhizopus oryzae, are suitable fungi for amylase production. While Maize cobs can be used as substrate for commercial enzymes production.