SCREENING AND ISOLATION OF ASPARAGINASE PRODUCERS FROM SOIL SOURCE AND ITS APPLICATION IN FOOD PRODUCTS

Abstract

Asparaginases have applications in the medical and food industry as part of an anticancer strategy and as a mechanism to reduce acrylamide content in food. Suspension of garden soil sample was plated on nutrient agar plate. Colonies were picked and screened for asparaginase activity on minimal media. Cultures were selected based on qualitative/quantitative assays. Culture characterization and identification was carried out with the help of microscopic and biochemical techniques, checking culture growth parameters on varied pH and temperatures. Application of the crude enzyme obtained from the asparaginase positive isolates was carried out by performing assays using a frozen ready-to-cook food sample - potato smileys. Thin Layer Chromatography (TLC) of untreated and treated food samples was also performed to determine the levels of asparagine in the samples. Out of a total of 36 isolates, four were selected for the study; which were later identified as Pseudomonas putida. The assays showed enzyme activity in all four cultures. Most of the isolates were found to grow at 37°C and pH of 7 and 10. Effect of the enzyme on asparagine content in the potato smiley was also detected. Treated samples showed more absorbance than the untreated sample. TLC method indicated that treated samples showed aspartic acid spots, thus showing effect of the enzyme while untreated sample plate showed no asparagine spots suggesting that low amounts of asparagine are present in the sample, or the raw potato used.