Sustainable Chemistry for the Environment (Jun 2025)
Production and characterization of L-asparaginase by Aspergillus niger: A sustainable use of pitaya (Hylocereus spp.) by-products
Abstract
The present study focused on the optimization of the L-asparaginase production by solid-state fermentation from Aspergillus niger INCQS 40018 (ATCC 1004) using pitaya by-product and the determination of its biochemical characterization. The L-asparaginase production was carried out at 25 °C using L-asparagine as an inducer to determine the best production time. The experiments of optimization process were performed in a 42 fold complete factorial design to evaluate the effect of the variables moisture and inducer concentration. For the enzyme characterization, the thermostability was studied with varying temperature of 20–70 °C, and the pH ranging from 3.0 to 11.0. The effect of NaCl, CaCl2, KCl, CuSO4 and EDTA at concentrations of 1 mM and 5 mM was also studied. The results showed that 36 h was the best time for L-asparaginase production and the variables studied were significant in the optimization process that presented an increase of 58.96 %. The enzyme produced obtained optimal activity at 40 °C and pH 5.0, and remained stable in the temperature range of 20 °C to 40 °C and pH of 4.0–5.0. Regarding the effect of the compounds studied, NaCl, CaCl2, and EDTA had an activating action on the enzyme, while KCl and CuSO4 showed an inhibitory action at the concentration of 5 mM. At a concentration of 1 mM, all the compounds inhibited the L-asparaginase. Overall, the results indicate the potential for the sustainable use of pitaya by-product for the L-asparaginase production with promising biotechnological capacity.
