Statistical optimization of glucose oxidase production from Aspergillus niger NRC9 under submerged fermentation using response surface methodology

Coproduction of inulinase and invertase by Galactomyces geotrichum in whey-based medium and evaluation of additional nutrients

The purpose of this research was to evaluate the suitability of whey as an effective medium for the coproduction of inulinase and invertase by an oleaginous yeast Galactomyces geotrichum and to investigate the effects of some additional carbon and nitrogen sources. The nutritional factors and composition of the medium have a great impact on the production pathways of microbial enzymes. To deepen the research, a Taguchi design was employed to quickly scan the best conditions. First, the cheese whey was partly deproteinized and investigated as the sole medium for the yeast. The next step was performed to study the effects of inulin, sucrose and lactose as carbon sources and ammonium sulfate, yeast extract and casein as nitrogen sources. All analyses (Taguchi and ANOVA) were performed using Minitab software. Whey-based medium without any additional carbon and nitrogen sources gave inulinase and invertase activities as 54.6 U/mL and 47.4 U/mL, respectively. Maximum inulinase activity was obtained as 77.9 U/mL using inulin as the carbon source without any nitrogen source. The highest I/S ratio was found as 2.08. On the other hand, the highest invertase activity was carried out as 50.85 U/mL in whey-based medium using lactose as carbon source without any additional nitrogen source. This is the first report about partly deproteinized whey-based medium utilization for simultaneous inulinase and invertase production by G. geotrichum TS-61. Moreover, the effects of carbon and nitrogen sources were investigated in detail.

Cost-effective, scalable production of glucose oxidase using Casuarina equisetifolia biomass and its application in the bio-Fenton oxidation process for the removal of trace organic contaminants from wastewater

This study focuses on using Casuarina equisetifolia biomass for pilot-scale glucose oxidase production from Aspergillus niger and its application in the removal of trace organic contaminants (TrOCs) from municipal wastewater through the bio-Fenton oxidation. The cost of glucose oxidase was 0.005 $/U, including the optimum production parameters, 10% biomass, 7% sucrose, 1% peptone, and 3% CaCO₃ at 96 h with an enzyme activity of 670 U/mL. Optimized conditions for H₂O₂ were 1 M glucose, 100 U/mL glucose oxidase, and 120 mins of incubation, resulting in 544.3 mg/L H₂O₂. Thus, H₂O₂ produced under these conditions lead to bio-Fenton oxidation resulting in the removal of 36-92% of nine TrOCs in municipal wastewater at pH 7.0 in 360 mins. Therefore, this work establishes the cost-effective glucose oxidase-producing H₂O₂ as an attractive bioremediating agent to enhance the removal of TrOCs in wastewater at neutral pH.

Insights into the Structures, Inhibitors, and Improvement Strategies of Glucose Oxidase

Glucose oxidase, which uses molecular oxygen as an electron acceptor to specifically catalyze the conversion of β-d-glucose to gluconic acid and hydrogen peroxide (H₂O₂), has been considered an important enzyme in increasing environmental sustainability and food security. However, achieving the high yield, low price and high activity required for commercial viability remains challenging. In this review, we first present a brief introduction, looking at the sources, characteristics, catalytic process, and applications of glucose oxidase. Then, the predictive structures of glucose oxidase from two different sources are comparatively discussed. We summarize the inhibitors of glucose oxidase. Finally, we highlight how the production of glucose oxidase can be improved by optimizing the culture conditions and microbial metabolic engineering.

Enzyme production ofd-gluconic acid and glucose oxidase: successful tales of cascade reactions

This review mainly focuses on the use of glucose oxidase in the production ofd-gluconic acid, which is a reactant of undoubtable interest in different industrial areas. As example of diverse enzymatic cascade reactions.

Optimization of pectinase immobilization on grafted alginate-agar gel beads by 24 full factorial CCD and thermodynamic profiling for evaluating of operational covalent immobilization

Pectinase produced by a honey derived from the fungus Aspergillus awamori KX943614 was covalently immobilized onto gel beads made of alginate and agar. Polyethyleneimine, glutaraldehyde, loading time and enzyme's units were optimized by 2⁴ full factorial central composite design (CCD). The immobilization process increased the optimal working pH for the free pectinase from 5 to a broader range of pH4.5-5.5 and the optimum operational temperature from 55°C to a higher temperature, of 60°C, which is favored to reduce the enzyme's microbial contamination. The thermodynamics studies showed a thermal stability enhancement against high temperature for the immobilized formula. Moreover, an increase in half-lives and D-values was achieved. The thermodynamic studies proved that immobilization of pectinase made a remarkable increase in enthalpy and free energy because of enzyme stability enhancement. The reusability test revealed that 60% of pectinase's original activity was retained after 8 successive cycles. This gel formula may be convenient for immobilization of other industrial enzymes.

Improvement Strategies, Cost Effective Production, and Potential Applications of Fungal Glucose Oxidase (GOD): Current Updates

Fungal glucose oxidase (GOD) is widely employed in the different sectors of food industries for use in baking products, dry egg powder, beverages, and gluconic acid production. GOD also has several other novel applications in chemical, pharmaceutical, textile, and other biotechnological industries. The electrochemical suitability of GOD catalyzed reactions has enabled its successful use in bioelectronic devices, particularly biofuel cells, and biosensors. Other crucial aspects of GOD such as improved feeding efficiency in response to GOD supplemental diet, roles in antimicrobial activities, and enhancing pathogen defense response, thereby providing induced resistance in plants have also been reported. Moreover, the medical science, another emerging branch where GOD was recently reported to induce several apoptosis characteristics as well as cellular senescence by downregulating Klotho gene expression. These widespread applications of GOD have led to increased demand for more extensive research to improve its production, characterization, and enhanced stability to enable long term usages. Currently, GOD is mainly produced and purified from Aspergillus niger and Penicillium species, but the yield is relatively low and the purification process is troublesome. It is practical to build an excellent GOD-producing strain. Therefore, the present review describes innovative methods of enhancing fungal GOD production by using genetic and non-genetic approaches in-depth along with purification techniques. The review also highlights current research progress in the cost effective production of GOD, including key advances, potential applications and limitations. Therefore, there is an extensive need to commercialize these processes by developing and optimizing novel strategies for cost effective GOD production.

Statistical optimization of fibrinolytic enzyme production by Pseudoalteromonas sp. IND11 using cow dung substrate by response surface methodology

Fibrinolytic enzymes are agents that dissolve fibrin clots. These fibrinolytic agents have potential use to treat cardiovascular diseases, such as heart attack and stroke. In the present article, a fibrinolytic enzyme producing Pseudoalteromonas sp. IND11 was isolated from the fish scales and optimized for enzyme production. Cow dung was used as a substrate for the production of fibrinolytic enzyme in solid-state culture. A two-level full factorial design was used for the screening of key ingredients while further optimization was carried out using the central composite design. Statistical analysis revealed that the second-order model is significant with model F-value of 6.88 and R² value of 0.860. Enzyme production was found to be high at pH 7.0, and the supplementation of 1% (w/w) maltose and 0.1% (w/w) sodium dihydrogen phosphate enhanced fibrinolytic enzyme production. The optimization of process parameters using response surface methodology resulted in a three-fold increase in the yield of fibrinolytic enzyme. This is the first report on production of fibrinolytic enzyme using cow dung substrate in solid-state fermentation.