Production of L-asparaginase by isolated Aspergillus species using SSF

K. B. Uppuluri¹,²*, S. V. Kalidindi¹, Sekhar P. V. G. V¹, Harish CH¹ and D. S. Rami Reddy²

¹Department of Biotechnology, Bapatla engineering College, Bapatla, 52101 (India) ²Centre for Biotechnology, Au College of Engineering, Andhra University, Visakhapatnam (India)

ABSTRACT: Acute lymphocytic leukemia is a common leukemia characterized by frequent infections and anaemia. Thousands of new cases are diagnosed each year worldwide. L-asparaginase (E.C.3.5.1.1), also known as L-asparagine amino hydrolase, is a potential anti tumor enzyme that catalyses the hydrolysis of L-asparagine into L-aspartic acid and ammonia. L-asparaginase production was investigated in the filamentous fungi on sesame cake using solid state fermentation(SSF).One-factor-at-a-time approach design was applied to optimize a solid-state fermentation using the sesame cake as a main substrate, for the production of L-asparaginase by isolated Aspergillus Species. Effect of Various environmental factors like Particle size of the solid medium, Moisture content, Incubation pH, Time and temperature and number of different nutritional supplements were verified on the activity and specific activity of extracellular enzyme, L-asparaginase. Among those pH, Particle size, moisture content, glucose, Ammonium sulphate and L-asparagine were the most significant factors improving enzyme production process. The second optimization step was carried out to identify the different sources of the three factors influencing the production of enzyme namely Glucose, ammonium sulphate and L-asparagine, that bringing about maximum L-asparaginase activity. Maximal enzyme activity (191.2 IU) has been detected under the following conditions, pH 6.5, temperature 32oC, incubation period 108 hours, particle size of 0.67 cm, moisture content of 1:1 (Media: buffer) when medium was supplemented with 3%w/w Fructose, 3%w/w Ammonium sulphate, 0.1%w/w L-Asparagine, 0.01% w/w Magnesium Sulphate,01% w/w sodium chloride and inoculum size of 1.5ml (1.6 X 103Spores/ml) which is nearly three folds the activity in basal medium .

KEYWORDS: L-asparaginase production; Aspergillus niger; Sesame cake; Solid-state fermentation

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