Evaluation of factors affecting L-asparaginase activity using experimental design

The present study aims for the purification and characterization of L-asparaginase produced by Fusarium solani. Microbial L-Asparaginase has attracted considerable attention, owing to the cost effective and eco-friendly nature. The most common use of asparaginases is as a processing aid in the manufacture of food. L-asparaginase used to reduce the formation of acrylamide, a suspected carcinogen, in starchy food products such as baked or fried snacks and biscuits. Extracellular L-asparaginase was produced by solid-state fermentation (SSF) using sequential statistical strategy as optimization for some vital factors; wheat bran concentration, fermentation time, moisture content, inoculum size, temperature, culture age and asparagine concentration which were adjusted by the sequential two design of response surface methodology. Fusarium solani produced the highest L-asparaginase level (254 I/U) using Placket-Burman design andimprovement up to 290 U/gds upon applying the Box-Behnken design. Partial purification of the enzyme using acetone was done, the specific activity increased to 709.24/mg in the fraction of 40–60% acetone The optimum temperature and pH of the enzyme were 40oC and 7, respectively. The Km and Vmax of the partially purified enzyme were 9.1×10−2 mμ and 20 U/mg proteins respectively. The impact of L-asparaginase on the acrylamide content reduction after high heat treatment in a model system as well as in potato based material was investigated.