Uncommon overoxidative catalytic activity in a new halo‐tolerant alcohol dehydrogenase. Issue 22 (11th September 2020)

• Record Type: Journal Article
• Authors: Contente, Martina L.; Fiore, Noemi; Cannazza, Pietro; Roura Padrosa, David; Molinari, Francesco; Gourlay, Louise; Paradisi, Francesca
• Is Part Of: ChemCatChem. Volume 12:Issue 22(2020)
• Page Start: 5679
• Page End: 5685
• Publication Date: 2020-09-11
• Subjects: Alcohol dehydrogenase -- Halomonas elongata -- Overoxidation -- Biocatalysis -- Aldoxymes synthesis; Catalysis -- Periodicals; 541.39505
• DOI: 10.1002/cctc.202001112
• Languages: English
• ISSNs: 1867-3880

Abstract

Abstract: Alcohol dehydrogenases (ADH) are versatile and useful enzymes employed as biocatalysts, especially for the selective oxidation of primary and secondary alcohols, and for the reduction of carbonyl moieties. A new alcohol dehydrogenase (HeADH‐II) has been identified from the genome of the halo‐adapted bacterium Halomonas elongata, which proved stable in the presence of polar organic solvents and salt exposure. Unusual for this class of enzymes, HeADH‐II lacks enantiopreference and is capable of oxidizing both alcohols and aldehydes, enabling a direct overoxidation of primary alcohols to carboxylic acids. HeADH‐II was coupled with a NADH‐oxidase from Lactobacillus pentosus ( Lp NOX) to increase the process yields and allowing recycling of the cofactor. The enzymatic oxidation of primary alcohols was also paired with in situ condensation of the intermediate aldehydes with hydroxylamine to prepare the corresponding aldoximes, with particular attention to perillartine (a powerful sweetener), whose enzymatic synthesis starting from natural sources, leads to an equally natural product. Abstract : Enzymatic catalysis : An unusual alcohol dehydrogenase has been identified from the halo‐adapted bacterium H. elongata . HeADH‐II shows a great stability to polar solvents and high salt concentration as well as uncommon characteristics such as the lack of enantiopreference and the capability of overoxidizing alcohols to carboxylic acids. To increase the process yields and allowing cofactor recycling, HeADH‐II was coupled with a NADH‐oxidase from L. pentosus ( Lp NOX).