title: Batch and fed-batch bioreactor studies for the enhanced production of glutaminase-free L-asparaginase from Pectobacterium carotovorum MTCC 1428.
abstract: The effect of dissolved oxygen (DO) level and pH (controlled/uncontrolled) was first studied to enhance the production of novel glutaminase-free L-asparaginase by Pectobacterium carotovorum MTCC 1428 in a batch bioreactor. The optimum level of DO was found to be 20%. The production of L-asparaginase was found to be maximum when pH of the medium was maintained at 8.5 after 12 h of fermentation. Under these conditions, P. carotovorum produced 17.97 U/mL of L-asparaginase corresponding to the productivity of 1497.50 U/L/h. The production of L-asparaginase was studied in fed-batch bioreactor by feeding L-asparagine (essential substrate for production) and/or glucose (carbon source for growth) at the end of the reaction period of 12 h. The initial medium containing both L-asparagine and glucose in the batch mode and L-asparagine in the feeding stream was found to be the best combination for enhanced production of glutaminase-free L-asparaginase. Under this condition, the L-asparaginase production was increased to 38.8 U/mL, which corresponded to a productivity of 1615.8 U/L/h. The production and productivity were increased by 115.8% and 7.9%, respectively, both of which are higher than those obtained in the batch bioreactor experiments.
authors.affiliation: a Biochemical Engineering Laboratory, Department of Biosciences and Bioengineering , Indian Institute of Technology , Guwahati , Assam , India.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Kumar
authors.affiliation: a Biochemical Engineering Laboratory, Department of Biosciences and Bioengineering , Indian Institute of Technology , Guwahati , Assam , India.
authors.forename: Ashish A
authors.initials: AA
authors.lastname: Prabhu
authors.affiliation: a Biochemical Engineering Laboratory, Department of Biosciences and Bioengineering , Indian Institute of Technology , Guwahati , Assam , India.
authors.forename: V Venkata
authors.initials: VV
authors.lastname: Dasu
authors.affiliation: a Biochemical Engineering Laboratory, Department of Biosciences and Bioengineering , Indian Institute of Technology , Guwahati , Assam , India.
authors.forename: Kannan
authors.initials: K
authors.lastname: Pakshirajan
mesh_terms: D001215:Asparaginase / Q000096:biosynthesis* / Q000378:metabolism; D019149:Bioreactors; D003470:Culture Media; D005972:Glutaminase / Q000378:metabolism; D016973:Pectobacterium carotovorum / Q000201:enzymology*
chemical_list: D003470:Culture Media; D001215:Asparaginase; D005972:Glutaminase
keywords: Antileukemic enzyme; L-asparaginase; Pectobacterium carotovorum; bioreactor; fed-batch fermentation