Recent developments in biocatalysis beyond the laboratory

Recent developments in biocatalysis, where implementation beyond the laboratory has been demonstrated, are explored: the use of transglutaminases to modify foods, reduce allergenicity and produce advanced materials, lipases for biodiesel production, and transaminases for biochemical production. The availability and application of enzymes at pilot and larger scale opens up possibilities for further improvements of biocatalyst-based processes and the development of new processes. Enzyme production, stability, activity, re-use, and product retrieval are common challenges for biocatalytic processes. We explore recent advances in biocatalysis within the process chain, such as protein engineering, enzyme expression, and biocatalyst immobilization, in the context of these challenges

Recent developments in biocatalysis beyond the laboratory

Recent developments in biocatalysis, where implementation beyond the laboratory has been demonstrated, are explored: the use of transglutaminases to modify foods, reduce allergenicity and produce advanced materials, lipases for biodiesel production, and transaminases for biochemical production. The availability and application of enzymes at pilot and larger scale opens up possibilities for further improvements of biocatalyst-based processes and the development of new processes. Enzyme production, stability, activity, re-use, and product retrieval are common challenges for biocatalytic processes. We explore recent advances in biocatalysis within the process chain, such as protein engineering, enzyme expression, and biocatalyst immobilization, in the context of these challenges

Biocatalytic versatility of engineered and wild-type tyrosinase from R-solanacearum for the synthesis of 4-halocatechols

We evaluated the kinetic characteristics of wild type (WT) and three engineered variants (RVC10, RV145, and C10_N322S) of tyrosinase from Ralstonia solanacearum and their potential as biocatalysts to produce halogenated catechols. RV145 exhibited a 3.6- to 14.5-fold improvement in catalytic efficiency (k (cat)/K (m)) with both reductions in K (m) and increases in k (cat) compared to WT, making it the best R. solanacearum tyrosinase variant towards halogenated phenols. RVC10 also exhibited increases in catalytic efficiency with all the tested phenols. A single-mutation variant (C10_N322S) exhibited the greatest improvement in k (cat) but lowest improvement in catalytic efficiency due to an increase in K (m) compared to WT. Consistent with kinetic characteristics, biotransformation experiments showed that RV145 was a superior biocatalyst in comparison to WT. To prevent through conversion of the catechol to quinone, ascorbic acid (AA) was added to the biotransformation medium in 1:2 (substrate:AA) ratio resulting in a catechol yield of gt 90%. Flask experiments with 10 mM 4-iodophenol and 10 mu g/mL of the RV145 enzyme yielded 9.5 mM 4-iodocatechol in the presence of 20 mM AA in 30 min. Similarly, 10 mM 4-fluorophenol was completely consumed by 20 mu g/mL of RV145 enzyme and yielded 9.2 mM 4-fluorocatechol in the presence of 20 mM AA in 80 min. The biotransformation of 20 mM 4-fluorphenol was incomplete (93%) and the yield of 4-flurocatechol was 87.5%. The 4-halophenol conversion rates and product yields obtained in this study are the highest reported using tyrosinase or any other enzyme

Potent anti-melanogenic activity and favorable toxicity profile of selected 4-phenyl hydroxycoumarins in the zebrafish model and the computational molecular modeling studies

7-Hydroxy-4-phenylcoumarin (7C) and 5,7-dihydroxy-4-phenylcoumarin (5,7C) have been evaluated as potential anti-melanogenic agents in the zebrafish (Danio rerio) model in comparison to commercially utilized depigmenting agents hydroquinone and kojic acid. 7C and 5,7C decreased the body pigmentation at 5 mu g/mL, while did not affect the embryos development and survival at doses lt = 50 mu g/mL and lt = 25 mu g/mL. Unlike hydroquinone and kojic acid, 4-phenyl hydroxycoumarins were no melanocytotoxic, showed no cardiotoxic side effects, neither caused neutropenia in zebrafish embryos, suggesting these compounds may present novel skin-whitening agents with improved pharmacological properties. Inhibition of tyrosinase was identified as the possible mode of anti-melanogenic action. Molecular docking studies using the homology model of human tyrosinase as well as adenylate cyclase revealed excellent correlation with experimentally obtained results