Li J, Gao K, Secundo F, Mao X. Biochemical characterization of two β-N-acetylglucosaminidases from Streptomyces violascens for efficient production of N-acetyl-d-glucosamine.
Food Chem 2021;
364:130393. [PMID:
34167004 DOI:
10.1016/j.foodchem.2021.130393]
[Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 05/27/2021] [Accepted: 06/14/2021] [Indexed: 11/16/2022]
Abstract
Chitin, one of the most abundant renewable biopolymers on Earth, is commercially available from crustacean wastes. One critical step in converting chitin to high-value products is its degradation by chitinolytic enzymes to N-acetyl-d-glucosamine (GlcNAc), which plays a significant role in functional food and pharmaceutical industries. Here, we cloned and biochemically characterized two novel β-N-acetylglucosaminidases named SvNag2557 (family-84) and SvNag4755 (family-3) from Streptomyces violascens ATCC 27968. Both SvNag2557 and SvNag4755 exhibited strict substrate specificity toward N-acetyl chitooligosaccharides with GlcNAc as the sole product. Thus, a one-pot production for pure GlcNAc from chitin by an enzyme cocktail reaction was further developed. Under the co-action of an endo-type chitinase SaChiA4 and SvNag2557 (mass ratio 1:2), the final conversion rates of colloidal chitin and ionic liquid pretreated chitin to GlcNAc were 80.2% and 73.8% with GlcNAc purities of 99.7% and 96.8%, respectively.
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