C.O. ONU , L.O. ENEJE , V. ANIAKU AND C.D. NWANI
Abstract
The effect of carbon sources on the production of raw starch digesting amylase was studied. Different starches from cassava, maize, sorghum, soluble starch, glucose and sucrose were used. The cassava starch was prepared by peeling, pulping, and sieving and later dried in the sun. The grain starches were prepared by milling the grains to powder and later sieved with muslin cloth before being dried. One milliliter (1mL) of a 1% solution of these starches was used. A basal medium made up of MgSO4.7H2O, NaCl, KH2PO4 and yeast extract all 0.1% in 100mL of de-ionized water was prepared, mixed and autoclaved at 121oC for 10mins but 110oC for the glucose. The prepared organism Aspergillus tamari was inoculated in each of the carbon sources. Shake flask fermentation lasting four days was carried out at 30oC with the choice carbon source incorporated into the basal medium to allow for the growth of the test organism, Aspergillus tamari. The pH and enzyme activity were then determined. From the results obtained the soluble starch was recorded the best carbon source at 0.625µmL amylase activity at pH of 6.25 and at 2% concentration. Thus, soluble starch supports most among many carbon sources studied for the growth of Aspergillus tamari in producing starch digesting amylase for industrial applications