Development of effective biotransformation process for benzohydroxamic acid production using Bacillus smithii IIIMB2907

Recombinant Amidases: Recent Insights and its Applications in the Production of Industrially Important Fine Chemicals

The current research for the synthesis of industrially important fine chemicals is more inclined towards developing enzyme-based processes. The biotransformation reactions wherein microbial cells/enzymes are used, have become essential in making the process efficient, green, and economical. Amongst industrially important enzymes, amidase is one of the most versatile tools in biocatalysis and biotransformation reactions. It shows broad substrate specificity and sturdy functional characteristics because of its promiscuous nature. Further, advancement in the area led to the development of amidase recombinant systems, which are developed using biotechnology and enzyme engineering tools. Additionally, recombinant amidases may be instrumental in commercializing the synthesis of fine chemicals such as hydroxamic acids that have a significant pharmaceutical market. Hence, the present review focuses on highlighting and assimilating the tools and techniques used in developing recombinant systems followed by their applications.

Microbial amidases: Characterization, advances and biotechnological applications

The amidases (EC 3.5.1.4) are versatile hydrolase biocatalysts that have been the attention of academia and industries for stereo-selective synthesis and bioremediation. These are categorized based on the amino acid sequence and substrate specificity. Notably, the Signature amidase family is distinguished by a characteristic signature sequence, GGSS(S/G)GS, which encompasses highly conserved Ser-Ser-Lys catalytic residues, and the amidases belonging to this family typically demonstrate a broad substrate spectrum activity. The amidases classified within the nitrilase superfamily possess distinct Glu-Lys-Cys catalytic residues and exhibit activity towards small aliphatic substrates. Recent discoveries have underscored the potential role of amidases in the degradation of toxic amides present in polymers, insecticides, and food products. This expands the horizons for amidase-mediated biodegradation of amide-laden pollutants and fosters sustainable development alongside organic synthesis. The burgeoning global production facilities are expected to drive a heightened demand for this enzyme, attributable to its promising chemo-, regio-, and enantioselective hydrolysis capabilities for a variety of amides. Advances in protein engineering have enhanced the catalytic efficiency, structural stability, and substrate selectivity of amidases. Concurrently, the heterologous expression of amidase genes sourced from thermophiles has facilitated the development of highly stable amidases with significant industrial relevance. Beyond their biotransformation capabilities concerning amides, through amido-hydrolase and acyltransferase activities, recent investigations have illuminated the potential of amidase-mediated degradation of amide-containing pollutants in soil and aquatic environments. This review offers a comprehensive overview of recent advancements pertaining to microbial amidases (EC 3.5.1.4), focusing on aspects such as their distribution, gene mining methodologies, enzyme stability, protein engineering, reusability, and biocatalytic efficacy in organic synthesis and biodegradation.