Statistical assessment of medium components by factorial design and surface methodology of L-Asparaginase production by isolated Streptomyces radiopugnans MS1 in submerged fermentation using Tapioca effluent

Abstract

Streptomyces radiopugnans MS1 was isolated from marine environment and identified as a potent strain for producing L-Asparaginase from Tapioca effluent an inexpensive substrate. To optimize the L-Asparaginase production of this bacterial strain, 23 fermentation variables were screened using a Plackett-Burman design and were then further optimized via response surface methodology based on a Box-/Behnken design. Four significant variables, i.e., Tapioca Effluent, Corn steep liquor, L-Aspaparagine and Areation, were selected. The optimum values of the tested variables by response surface methodology were; Tapioca Effluent, 5 (% v/v); Corn steep liquor, 2 (% w/v); L-Aspaparagine, 0.003 (% w/v); Aeration, 0.7 (vvm) found to be optimum for L-Asparaginase production. The experimental result (19.5 IU mL-1) in a medium optimized for L-Asparaginase production was in good agreement with the predicted value of a quadratic model (19.8 IU -1). A verification experiment was carried out to examine model validation and revealed more than 99% validity. The model was very satisfactory as the coefficient of determination was 0.99. L-Asparaginase production in the optimized medium (19.5±0.33 IU -1) increased 4.81-fold over that of the basal medium (4.05±0.84 IU -1) in the fermenter. © 2012 Knowledgia Review.