STUDY OF L-ASPARAGINASE FROM RHIZOBIUM PUSENSE STRAIN SS1 AND ITS APPLICATION IN MITIGATION OF ACRYLAMIDE FROM FRIED POTATO CHIPS

Abstract

Acrylamide (carcinogen, neurotoxin) is formed in starchy and carbohydrate rich foods because of Maillard reaction wherein L-asparagine and reducing sugar present in high amount react with each other. In this study, L-asparaginase enzyme was employed to lower acrylamide content from potato chips before frying. L-asparaginase producing bacteria (Rhizobium pusense Strain SS1, GenBank accession no. MH611376.1) was isolated from garden soil. Enzyme production media was optimized with 2% starch, 0.5% L-asparagine, pH 6.5 - 7.5, temperature of 28°C and agitation of 150 rpm, which gave 2200 unit/ml. The enzyme was partially purified with Ammonium Sulphate precipitation and dialysis to obtain enzyme activity of 1466 units/ml and specific activity of 36.60 units/mg. Molecular weight of the enzyme was found to be 37.5 kDa by SDS-PAGE. Enzyme kinetic studies showed the enzyme optimally active at pH 8.6, with temperature of 37°C and maximum substrate concentration of 190mM of L-Asparagine.Sliced potato chips were treated with partially purified enzyme. After frying the Acrylamide content was analysed with HPLC. There was 99.92% reduction in acrylamide content in enzyme treated potato chips sample. This study reports L-Asparaginase enzyme production by Rhizobium pusense Strain SS1for the first time and suggests a potential agent in mitigating acrylamide content from carbohydrate rich foods to be used in food industry.