Biocatalysis

The generation of organic wastes, such as sludge from wastewater treatment plants and food waste, is an inevitable byproduct of human activity. In line with the Federal Pollution Prevention Act of 1990 and the principles of Green Chemistry, waste that cannot be prevented or recycled must be managed in an environmentally sustainable manner. Conventional waste management methods, including incineration and landfilling, pose significant environmental risks, such as greenhouse gas emissions and soil and groundwater contamination.

Many halogenated compounds are used as intermediates in the synthesis of compounds of interest to the chemical, pharmaceutical industries; however, chemical halogenation involves the use of high-cost reagents that are often harmful to the environment.

Electrochemical methods like electrocoagulation (EC) can remove a vast array of compounds from wastewater but are not ideal for emerging pollutants found at low concentrations (ng/L to μg/L). In contrast, enzymes are known to effectively target these pollutants, but their performance can be hindered in complex water matrices. This work explores a biocatalytic treatment assisted by electrochemical processes to remove two emerging pollutants, Bisphenol A (BPA) and Triclosan (TCS) from municipal wastewater.

Use of lignocellulosic biomass in continuous processes in biorefineries poses challenges due to its recalcitrant properties, feedstock variability, and materials handling of solids at large scale. Limitations include lignin derived inhibitors, and resistance to mixing due to rheological properties of lignocellulosic particulates at high solids loadings.

Over the past two decades, there has been a significant surge of interest in the field of ultraviolet and/or visible (UV/vis) light photocatalysis. UV-vis irradiation merged with noble metal-based photosensitizers of Ru, Ir as catalysts is most useful combination in this segment as these metal photocatalysts mostly absorb in the UV/vis region. However, high energy UV/vis irradiation sources as well as the noble-metal based photosensitizer are not considered as green.

Traditional methods of oxidizing alcohols often rely on toxic reagents, as well as high pressures and temperatures, which can be hazardous. In contrast, biocatalysis utilizes enzymes as natural and non-toxic catalysts, typically under milder reaction conditions. This study aims to perform oxidation reactions of primary and secondary alcohols using enzymes as catalysts.

Carbohydrate mimetics play vital roles in various cell-mediated processes due to their structural resemblance to natural sugars, yet they exhibit distinct properties. Thioglycosides, in which an exocyclic oxygen atom is replaced by sulfur, are recognized as key building blocks in the preparation of glycans and the development of novel monosaccharides. These compounds serve as valuable intermediates in carbohydrate chemistry, being widely utilized in sequential glycosylation strategies for oligosaccharide synthesis.

Key points

• Biocatalysis refers to the use of natural catalysts, such as protein enzymes, to conduct chemical reactions. 
• These biocatalysts are particularly advantageous in chemical processes because they combine the selectivity of directing groups and the efficiency of catalysts into single reagents. 
• Enzymes can also be combined with other enzymes in one-pot reactions, allowing for complex multi-step syntheses.