Extracellular amylase production of a thermotolerant Fusarium sp: isolated from Eastern Nigerian soil

Abstract

In this work, an α- amylase producing Fusarium sp. was isolated from the soil at 50 0C. Growth and enzyme production occurred at 30, 45 and 55 ºC. Soybean meal at 1% concentration, supplemented with 0.2% NH4Cl and 2.5% corn starch elicited the highest amylase yield. Optimum pH for the enzyme was pH 6.5 which retained over 60% of its activity after 24 h incubation at the pH range of 4.5-7.0. The enzyme showed high activity from 40-70 0C with optimal activity at 50 ºC and 78% activity was retained after incubation at 70 ºC for 30min. Catalytic function of the crude amylase was stimulated by Mg (136%), Ca (118%) and Zn (118%) at 2mM concentrations. The enzyme hydrolyzed cassava, potato and yam starches effectively.