Peculiarities and systematics of microbial diglycosidases, and their applications in food technology

Abstract

Diglycosidases are endo-β-glucosidases that hydrolyze the heterosidic linkage of diglycoconjugates, thereby releasing in a single reaction the disaccharide and the aglycone. Plant diglycosidases belong to the glycoside hydrolase family 1 and are associated with defense mechanisms. Microbial diglycosidases exhibit higher diversity-they belong to the families 3, 5, and 55-and play a catabolic role. As diglycoconjugates are widespread in the environments, so are the microbial diglycosidases, which allow their utilization as nutritional source and carbon recycling. In the last 10 years, six microbial diglycosidases have been sequenced, and for two of them, the three-dimensional structure has been elucidated. This knowledge allowed the identification of their diverse phylogenetic origin, and gave insights into the understanding of the substrate specificity. Here, the last advances and the applications of microbial diglycosidases are reviewed. Key points• Substrate specificity and phylogenetic relationships of diglycosidases are reviewed.• On-going and potential applications of diglycosidases are discussed.

Molecular Cloning and Functional Characterization of a β-Glucosidase Gene to Produce Platycodin D in Platycodon grandiflorus

“…These enzymes are involved in glycolipids breakdown and glucose release in plants to meet their metabolic needs (e.g., for cell growth and wall remodeling; Chuenchor et al, 2008 ; Horikoshi et al, 2022 ). β-glucosidases also display a range of aglycone specificities, a few of which show almost absolute specificity for one sugar and one aglycone, while others accept a range of either glycones or aglycones, or both ( Baglioni et al, 2021 ; Dziadas et al, 2021 ; Prieto et al, 2021 ). They have been extensively studied in the biotransformation of PE to PD.…”

Microbial Deglycosylation of Plant Metabolites: A Case Study with Actinoplanes missouriensis 431T

“…−) are a widespread group of enzymes, which find several applications in industrial biotransformations . Historically, the major interest has been placed in endo-glucanases (polysaccharidases) such as amylases and pectinases for food processing, xylanases for bleaching of pulp and paper, and cellulases for biofuel production. − More recently, enzymes that hydrolyze glycoconjugates have gained interest for the biotransformation of various plant-based foods. , …”

“…First, it has been postulated to occur via monoglycosidases: an α- l -rhamnosidase (EC 3.2.1.40) catalyzes the hydrolysis of terminal α- l -rhamnose residues and, subsequently, a β- d -glucosidase (EC 3.2.1.21) catalyzes the hydrolysis of terminal β- d -glucose residues. , Enzymatic preparations such as “hesperidinase” or “naringinase” (mixtures of α- l -rhamnosidase and β- d -glucosidase activities) are commercialized for processing of plant-based foods and synthesis of pharmaceutical products. , Likewise, “pectinases”, which are generally described as a mixture of polysaccharide hydrolases, also contain a pool of exo-glycoside hydrolases, including α- l -rhamnosidase and β- d -glucosidase activities, for debranching hairy regions of pectin . Second, the diglycosidase hesperidin 6- O -α- l -rhamnosyl-β- d -glucosidase (EC 3.2.1.168, αRβG) has been reported as produced by Acremonium sp. DSM 24697 and Actinoplanes missouriensis 431 T .…”

Two fungal flavonoid-specific glucosidases/rutinosidases for rutin hydrolysis and rutinoside synthesis under homogeneous and heterogeneous reaction conditions

“…The members of the glycoside hydrolase family 5–23 (GH5-23) belong to the diverse group of diglycosidases, which accept diglycosides such as 2 – 5 as substrates (Fig. 1 ) (Koseki et al 2018 ; Baglioni et al 2021 ). So far, two out of six characterized GH5-23 enzymes have been shown to catalyze the hydrolysis of both flavonoid glucosides ( e.g ., 1 ) and flavonoid rutinosides ( e.g ., 2 ) (Pachl et al 2020 ; Makabe et al 2021 ).…”