Immobilized enzymes from Geotrichum spp. improve wine quality

Recent Advances and Perspectives on Food-Grade Immobilisation Systems for Enzymes

The use of enzyme immobilisation is becoming increasingly popular in beverage processing, as this method offers significant advantages, such as enhanced enzyme performance and expanded applications, while allowing for easy process termination via simple filtration. This literature review analysed approximately 120 articles, published on the Web of Science between 2000 and 2023, focused on enzyme immobilisation systems for beverage processing applications. The impact of immobilisation on enzymatic activity, including the effects on the chemical and kinetic properties, recyclability, and feasibility in continuous processes, was evaluated. Applications of these systems to beverage production, such as wine, beer, fruit juices, milk, and plant-based beverages, were examined. The immobilisation process effectively enhanced the pH and thermal stability but caused negative impacts on the kinetic properties by reducing the maximum velocity and Michaelis-Menten constant. However, it allowed for multiple reuses and facilitated continuous flow processes. The encapsulation also allowed for easy process control by simplifying the removal of the enzymes from the beverages via simple filtration, negating the need for expensive heat treatments, which could result in product quality losses.

Optimization of κ-Selenocarrageenase Production by Pseudoalteromonas sp. Xi13 and Its Immobilization

The bioenzymatic production of selenium oligosaccharides addresses the problems resulting from high molecular weight and poor water solubility of κ-selenocarrageenan, and lays foundation for its application as adjuvant drugs for cancer treatment and food additive. κ-selenocarrageenase extracted from Pseudoalteromonas sp. Xi13 can degrade κ-selenocarrageenan to selenium oligosaccharides. The maximum optimized κ-selenocarrageenase activity using Response Surface Methodology (RSM) was increased by 1.4 times, reaching 8.416 U/mL. To expand applications of the κ-selenocarrageenase in industry, the preparation conditions of it in either lyophilized or immobilized form were investigated. The activity recovery rate of the lyophilized enzyme was >70%, while that of the immobilized enzyme was 62.83%. However, the immobilized κ-selenocarrageenase exhibits good stability after being reused four times, with 58.28% of residual activity. The selenium content of κ-selenocarrageenan oligosaccharides degraded by the immobilized κ-selenocarrageenase was 47.06 µg/g, 8.3% higher than that degraded by the lyophilized enzyme. The results indicate that the immobilized κ-selenocarrageenase is suitable for industrial applications and has commercial potential.

Enhancing stability and by-product tolerance of β-glucuronidase based on magnetic cross-linked enzyme aggregates

β-glucuronidase is an important catalyst which is highly specific for β-glucuronides. Here, we constructed magnetic cross-linking β-glucuronidase aggregates (MCLEAs) to for the production of glycyrrhetinic acid (GA). Before crosslinking via glutaraldehyde, we used carbodiimide to enhance the interaction between enzymes and carboxyl-functionalized Fe₃O₄, efficiently improving the activity recovery. Compared to free enzymes, both k_cat and k_cat/K_m enhanced, indicating that crosslinking and aggregation brought higher catalytic efficiency to enzymes. MCLEAs enhanced pH and thermal stabilities and retained 63.3% of catalytic activity after 6 cycles. More importantly, it was first found that the glucuronic acid tolerance of β-glucuronidase after the formation of MCLEAs enhanced 221.5% in 10 mM of glucuronic acid. According to the Raman spectroscopy, the ordered structure of β-glucuronidase increased from 43.9% to 50.6% after immobilization, which explained the increased stability and tolerance. To sum up, MCLEAs provided an efficient strategy for immobilization of enzymes, which enhanced stability and glucuronic acid tolerance of enzymes. It might be an effective solution to the serious inhibition caused by by-products during the preparation of aglycone from natural glycosides, having a significant applied prospect in industry.

Biocatalysis in the winemaking industry: Challenges and opportunities for immobilized enzymes

Enzymes are powerful catalysts already being used in a large number of industrial processes. Impressive advantages in enzyme catalysts improvement have occurred in recent years aiming to improve their performance under harsh operation conditions far away from those of their cellular habitat. Production levels of the winemaking industry have experienced a remarkable increase, and technological innovations have been introduced for increasing the efficiency at different process steps or for improving wine quality, which is a key issue in this industry. Enzymes, such as pectinases and proteases, have been traditionally used, and others, such as glycosidases, have been more recently introduced in the modern wine industry, and many dedicated studies refer to the improvement of enzyme performance under winemaking conditions. Within this framework, a thorough review on the role of enzymes in winemaking is presented, with special emphasis on the use of immobilized enzymes as a significant strategy for catalyst improvement within an industry in which enzymes play important roles that are to be reinforced paralleling innovation.