Biochemical Characterization of a Novel Exo-Type PL7 Alginate Lyase VsAly7D from Marine Vibrio sp. QY108

• Published in: International journal of molecular sciences 2021-08, Vol.22 (16), p.8402
• Main Authors: Zhang, Fengchao, Fu, Zheng, Tang, Luyao, Zhang, Zhelun, Han, Feng, Yu, Wengong
• Format: Article
• Language: English
• Subjects: Algae; Alginate lyase; Alginates; Alginates - metabolism; Alginic acid; Amino Acid Sequence; Amino acids; Bacteria; Bacterial Proteins - metabolism; Biodiesel fuels; Biofuels; Carbohydrates; Cell walls; Cold; E coli; Enzymes; Escherichia coli - metabolism; Ethanol; Glucuronic Acid - metabolism; Hydrogen-Ion Concentration; Industrial production; Molecular weight; Monosaccharides; Monosaccharides - metabolism; Phaeophyceae; Phaeophyceae - microbiology; Phylogenetics; Polysaccharide-Lyases - metabolism; Proteins; Renewable resources; Vibrio; Vibrio - metabolism
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms22168402

Brown algae is a kind of renewable resource for biofuels production. As the major component of carbohydrate in the cell walls of brown algae, alginate can be degraded into unsaturated monosaccharide by exo-type alginate lyases, then converted into 4-deoxy-L- -5-hexoseulose uronate (DEH) by a non-enzyme reaction, which is an important raw material for the preparation of bioethanol. In our research, a novel exo-type alginate lyase, VsAly7D, belonging to the PL7 family was isolated from marine bacterium sp. QY108 and recombinantly expressed in . The purified VsAly7D demonstrated the highest activity at 35 °C, whereas it still maintained 46.5% and 83.1% of its initial activity at 20 °C and 30 °C, respectively. In addition, VsAly7D exhibited the maximum activity under alkaline conditions (pH 8.0), with the simultaneously remaining stability between pH 8.0 and 10.0. Compared with other reported exo-type enzymes, VsAly7D could efficiently degrade alginate, poly-β-D-mannuronate (polyM) and poly-α-L-guluronate (polyG) with highest specific activities (663.0 U/mg, 913.6 U/mg and 894.4 U/mg, respectively). These results showed that recombinant VsAly7D is a suitable tool enzyme for unsaturated alginate monosaccharide preparation and holds great promise for producing bioethanol from brown algae.