EFFECT OF POTATO DEXTROSE AGAR, CORN MEAL AGAR AND TEMPERATURE

ABSTRACT

Micro-organisms are commonly presents in food. With respects to their characteristics and growth micro-organisms can serve as pathogens, commensal or food cultures. For this study the primary objective was to determine the effect of Potato dextrose agar, Corn meal agar and temperature on the mycelia growth rate for four isolates of common molds. The fungi isolate used include Aspergillus niger, Aspergillus nidulans, Aspergillus flavus and Penicilium oxalicum. These isolates were obtained from yam peels, groundnuts, orange and onion gotten from food stuff sellers in Uselu market, Egor Local Government Area of Benin City, Edo State. Tissue culture technique was employed for the Isolation. The Mycelial growth rate of the four isolates were evaluated on Potato dextrose agar, and Corn meal agar commercially prepared. Temperature of 4, 28 and 37°C effect was evaluated against the mycelia growth rate on the two media using the four common molds. The effect of temperature and nutrient status was compared on the two media. Potato dextrose agar, and Corn meal agar caused a significant difference in the isolates of the radial mycelia growth rate used. As the temperature of the isolates condition increased Aspergillus nidulans and Aspergillus flavus were the most favourable Isolates for fast radial growth of mycelium. While Pencilium oxalicum was the least. The growth rate for of the molds was medium dependent. Whereas, the effect temperature was a crucial criteria as isolates were found growing well at 4˚C or 37˚C but there was variation of mycelial growth at 28˚C for all isolates.