Comparative Evaluation of the Growth Parameters for Enhanced Extracellular L-Asparaginase Production by Locally Isolated Rossellomorea marisflavi Strain
Comparative Evaluation of the Growth Parameters for Enhanced Extracellular L-Asparaginase Production by Locally Isolated Rossellomorea marisflavi Strain
Iqra Javed, Beenish Maqsood* and Muhammad Khurshid*
ABSTRACT
L-asparaginase (EC 3.5.1.1) has gained prominence as an industrial enzyme in the recent decades. It is notable for its use as an anticancer drug and an acrylamide mitigator in the food industry. The screening of L-asparaginase from new microbial sources, with greater yield and fewer drawbacks is greatly appreciated. The present work attempts to screen and identify L-asparaginase producing bacteria from soil, as well as to optimize the bioprocess parameters for higher yield of extracellular L-asparaginase. For this purpose, fifteen isolates were screened by rapid plate assay. The two microbial colonies representing widest pink zone around them were identified as Rossellomorea marisflavi and Bacillus cereus, based on 16S ribosomal RNA gene sequencing results. B. cereus and R. marisflavi produced maximum L-asparaginase at neutral pH and pH 8 respectively, when cultured for 36 h using 1.5% inoculum size. For optimal L-asparaginase production, R. marisflavi required 40ºC while B. cereus preferred 37ºC temperature. Best liquid media was Czapek 2 for R. marisflavi that produced 583 U/mg enzyme and TSB for B. cereus that gave 250 U/mg L-asparaginase; while Corn cob as solid substrate facilitated L-asparaginase production maximally by both strains. The supplementation of metal ions altered L-asparaginase production differently. However, addition of Mg+2 under optimized fermentation conditions magnified L-asparaginase production to 882.35 U/mg by R. marisflavi and to 414.47 U/mg by B. cereus. Therefore, this study served to provide two isolates from Bacillaceae family that can utilize inexpensive substrates and Mg+2 to give enhanced L-asparaginase production under optimized fermentation conditions for future commercial applications.
To share on other social networks, click on any share button. What are these?
