Production, characterization and techno-economic evaluation of Aspergillus fusant l-asparaginase

AMB Express

Original Article

Andrew Amenaghawon¹  Agnes Antai²  Marcus Asuquo³  Joseph Essien⁴  Juliet Iheanacho⁵  Joyce Etiosa⁵  Atim Asitok⁶  Sylvester Antai⁶  Maurice Ekpenyong⁶  Ernest Akwagiobe⁷  Anitha Rao⁷  David Ubi⁷ 

[1] Department of Chemical Engineering, University of Benin, Benin City, Nigeria;Department of Economics, Faculty of Social Sciences, University of Calabar, Calabar, Nigeria;Department of Hematology, University of Calabar Teaching Hospital, Calabar, Nigeria;Department of Microbiology, Faculty of Science, University of Uyo, Uyo, Nigeria;Environmental Microbiology and Biotechnology Unit, Department of Microbiology, University of Calabar, Calabar, Nigeria;Environmental Microbiology and Biotechnology Unit, Department of Microbiology, University of Calabar, Calabar, Nigeria;University of Calabar Collection of Microorganisms (UCCM), Department of Microbiology, University of Calabar, Calabar, Nigeria;Industrial Microbiology and Biotechnology Unit, Department of Microbiology, Faculty of Biological Sciences, University of Calabar, Calabar, Nigeria;

关键词: Protoplast fusion;    -ASNase;    Sensitivity analysis;    Anti-leukemic activity;    Acrylamide mitigation;    Techno-economics;   

DOI  :  10.1186/s13568-022-01505-8

 received in 2022-10-10, accepted in 2022-12-21,  发布年份 2022

来源: Springer

【 摘 要 】

Protoplast fusion is one of the most reliable methods of introducing desirable traits into industrially-promising fungal strains. It harnesses the entire genomic repertoire of fusing microorganisms by routing the natural barrier and genetic incompatibility between them. In the present study, the axenic culture of a thermo-halotolerant strain of Aspergillus candidus (Asp-C) produced an anti-leukemic l-asparaginase (l-ASNase) while a xylan-degrading strain of Aspergillus sydowii (Asp-S) produced the acrylamide-reduction type. Protoplast fusion of the wild strains generated Fusant-06 with improved anti-leukemic and acrylamide reduction potentials. Submerged fed-batch fermentation was preferred to batch and continuous modes on the basis of impressive techno-economics. Fusant-06 l-ASNase was purified by PEG/Na+ citrate aqueous two-phase system (ATPS) to 146.21-fold and global sensitivity analysis report revealed polymer molecular weight and citrate concentration as major determinants of yield and purification factor, respectively. The enzyme was characterized by molecular weight, amino acid profile, activity and stability to chemical agents. Michaelis–Menten kinetics, evaluated under optimum conditions gave Km, Vmax, Kcat, and Kcat/Km as 6.67 × 10–5 M, 1666.67 µmolmin−1 mg−1 protein, 3.88 × 104 min−1 and 5.81 × 108 M−1.min−1 respectively. In-vitro cytotoxicity of HL-60 cell lines by Fusant-06 l-ASNase improved significantly from their respective wild strains. Stability of Fusant-06 l-ASNase over a wide range of pH, temperature and NaCl concentration, coupled with its micromolar Km value, confers commercial and therapeutic value on the product. Free-radical scavenging and acrylamide reduction activities were intermediate and the conferred thermo-halo-stability could be exploited for sustainable clinical and food industry applications.

【 授权许可】

CC BY   
© The Author(s) 2023

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