A Novel Multifunctional ?-N-Acetylhexosaminidase Revealed through Metagenomics of an Oil-Spilled Mangrove.

ABSTRACT: The use of culture-independent approaches, such as metagenomics, provides complementary access to environmental microbial diversity. Mangrove environments represent a highly complex system with plenty of opportunities for finding singular functions. In this study we performed a functional screening of fosmid libraries obtained from an oil contaminated mangrove site, with the purpose of identifying clones expressing hydrolytic activities. A novel gene coding for a ?-N-acetylhexosaminidase with 355 amino acids and 43KDa was retrieved and characterized. The translated sequence showed only 38% similarity to a ?-N-acetylhexosaminidase gene in the genome of Veillonella sp. CAG:933, suggesting that it might constitute a novel enzyme. The enzyme was expressed, purified, and characterized for its enzymatic activity on carboxymethyl cellulose, p-Nitrophenyl-2acetamide-2deoxy-?-d-glucopyranoside, p-Nitrophenyl-2acetamide-2deoxy-?-d-galactopyranoside, and 4-Nitrophenyl ?-d-glucopyranoside, presenting ?-N-acetylglucosaminidase, ?-glucosidase, and ?-1,4-endoglucanase activities. The enzyme showed optimum activity at 30 °C and pH 5.5. The characterization of the putative novel ?-N-acetylglucosaminidase enzyme reflects similarities to characteristics of the environment explored, which differs from milder conditions environments. This work exemplifies the application of cultivation-independent molecular techniques to the mangrove microbiome for obtaining a novel biotechnological product.

SUBMITTER: Soares FL 

PROVIDER: S-EPMC5615308 | biostudies-literature | 2017 Jul

REPOSITORIES: biostudies-literature