Isolation and screening of l-asparaginase free of glutaminase and urease from fungal sp.

Abstract

l-Asparaginase is a chemotherapeutic drug used in the treatment of acute lymphoblastic leukaemia (ALL), a malignant disorder in children. l-Asparaginase helps in removing acrylamide found in fried and baked foods that is carcinogenic in nature. l-Asparaginase is present in plants, animals and microbes. Various microorganisms such as bacteria, yeast and fungi are generally used for the production of l-asparaginase as it is difficult to obtain the same from plants and animals. l-Asparaginase from bacteria causes anaphylaxis and other abnormal sensitive reactions due to low specificity to asparagine. Toxicity and repression caused by bacterial l-asparaginase shifted focus to eukaryotic microorganisms such as fungi to improve the efficacy of l-asparaginase. Clinically available l-asparaginase has glutaminase and urease that may lead to side effects during treatment of ALL. Current work tested 45 fungal strains isolated from soil and agricultural residues. Isolated fungi were tested using conventional plate assay method with two indicator dyes, phenol red and bromothymol blue (BTB), and results were compared. l-Asparaginase activity was measured by cultivating in modified Czapek–Dox medium. Four strains have shown positive result for l-asparaginase production with no urease or glutaminase activity, among these C7 has high enzyme index of 1.57 and l-asparaginase activity of 33.59 U/mL. l-Asparaginase production by C7 was higher with glucose as carbon source and asparagine as nitrogen source. This is the first report focussing on fungi that can synthesize l-asparaginase of the desired specificity. Since the clinical toxicity of l-asparaginase is attributed to glutaminase and urease activity, available evidence indicates variants negative for glutaminase and urease would provide higher therapeutic index than variants positive for glutaminase and urease.

Production, characterization and bioinformatics analysis of l-asparaginase from a new Stenotrophomonas maltophilia EMCC2297 soil isolate

“…In the present study dextrose proved to have a positive effect on l-asparaginase biosynthesis by the test organism as it increased the production level of this enzyme. Other authors also reported that dextrose increases the production of l-asparaginase as in case of Aeromonas sp., Aspergillus terreus (Amena et al 2010;Doriya and Kumar 2016;El-Hefnawy et al 2015;Gurunathan and Sahadevan 2011;Varalakshmi and Raju 2013). However, other carbohydrate sources were reported for their enhancing effect on l-asparaginase biosynthesis as in case of sucrose and sorbitol for Streptomyces tendae (Kavitha and Vijayalakshmi 2010) and lactose in case of E. coli (Bahrani 2016).…”

Screening and optimizing fermentation production ofl‐asparaginase byAspergillus terreusstrain S‐18 isolated from the Brazilian Caatinga Biome

“…L-ASNase produced by the A. terreus strain S-18 showed low L-GLUase activity (0Á15 U g À1 ), indicating that the enzyme of eukaryotic origin has an advantage over the Escherichia coli native L-ASNase (EcASNase 2) that has notable L-GLUase activity (Campbell and Mashburn 1969;Wriston and Yellin 1973). Studies have demonstrated the production of L-ASNase with low L-GLUase activity from eukaryotic sources (Huang et al 2014;Doriya and Kumar 2016), although some studies have shown that L-GLUase activity is important for the overall efficacy of treatment and serves as a positive modulator of L-ASNase activity in sub-micromolar concentrations of asparagine in the serum of patients undergoing treatment (Anishkin et al 2015). Therefore, A. terreus strain S-18 presents as a new L-ASNase eukaryotic source.…”

“…Studies have demonstrated the production of l ‐ASNase with low l ‐GLUase activity from eukaryotic sources (Huang et al . ; Doriya and Kumar ), although some studies have shown that l ‐GLUase activity is important for the overall efficacy of treatment and serves as a positive modulator of l ‐ASNase activity in sub‐micromolar concentrations of asparagine in the serum of patients undergoing treatment (Anishkin et al . ).…”

Screening of Bacteria Producing Asparaginase Free of Glutaminase and Urease from Hot Springs in West Sulawesi

“…Phenol red was pH indicator which would be turned to yellow at acidic pH and turn into pink at alkaline pH. The released ammonia will change the color of the medium from yellow to pink indicating the enzymatic activity due to different nitrogen sources (Doriya & Kumar, 2016;Phang et al, 2018;Sudhir et al, 2012).…”