A comprehensive review on microbial l-asparaginase: Bioprocessing, characterization, and industrial applications.

l-Asparaginase (E.C.3.5.1.1.) is a vital enzyme that hydrolyzes l-asparagine to l-aspartic acid and ammonia. This property of l-asparaginase inhibits the protein synthesis in cancer cells, making l-asparaginase a mainstay of pediatric chemotherapy practices to treat acute lymphoblastic leukemia (ALL) patients. l-Asparaginase is also recognized as one of the important food processing agent. The removal of asparagine by l-asparaginase leads to the reduction of acrylamide formation in fried food items. l-Asparaginase is produced by various organisms including animals, plants, and microorganisms, however, only microorganisms that produce a substantial amount of this enzyme are of commercial significance. The commercial l-asparaginase for healthcare applications is chiefly derived from Escherichia coli and Erwinia chrysanthemi. A high rate of hypersensitivity and adverse reactions limits the long-term clinical use of l-asparaginase. Present review provides thorough information on microbial l-asparaginase bioprocess optimization including submerged fermentation and solid-state fermentation for l-asparaginase production, downstream purification, its characterization, and issues related to the clinical application including toxicity and hypersensitivity. Here, we have highlighted the bioprocess techniques that can produce improved and economically viable yields of l-asparaginase from promising microbial sources in the current scenario where there is an urgent need for alternate l-asparaginase with less adverse effects.

A reliable assay for ensuring the biological activity of anti T lymphocyte immunoglobulin as an alternate to compendial flow cytometry method.

The assay of Anti T lymphocyte immunoglobulin for final drug product testing is carried out using flow cytometry on Peripheral Blood Mononuclear Cells (PBMCs) as specified in European and British Pharmacopeia. An alternate assay was developed wherein the potency based quality control evaluation of Anti T lymphocyte immunoglobulin is carried out by measuring complement dependent cytotoxicity (CDC) using fluorescent resazurin dye. The reported bioassay was specific, linear (R2 = 0.98), precise (%GCV for repeatability was 3.54% and intermediate precision was 4.27%) and accurate with relative bias of -5.54%. On the basis of results obtained from the repeated performances on single available product, system suitability criteria and sample acceptance criteria were proposed wherein Slope from 4 PL curve fit results for Reference Standard (RS) should be > 0.9, EC50 for RS should lie between 0.264 and 1.131 µg/ml and fold response should be > 2. Confidence interval range and estimated relative potency range obtained from the method validation were narrower than those mentioned for compendial method.