title: Characterization of an alkaline β-agarase from Stenotrophomonas sp. NTa and the enzymatic hydrolysates.
abstract: An extracellular agarase from marine bacterium Stenotrophomonas sp. NTa was purified to homogeneity. By size exclusion chromatography and SDS-PAGE analysis, the enzyme was determined to be a homodimer with monomeric molecular mass of 89.0 kDa. The optimal temperature and pH of strain NTa agarase were 40 °C and 10.0, respectively. It exhibited striking stability across a wide pH range of 5.0-11.0. Agarase from Stenotrophomonas sp. NTa had a relatively good resistance against the detected inhibitors, detergents and urea denaturant. The Km and Vmax for agar were 11.3mg/ml and 25.4 U/mg, respectively. Thin layer chromatography analysis, mass spectrometry, and enzyme assay using p-nitrophenyl-α/β-D-galactopyranoside revealed that strain NTa agarase was a β-agarase that degraded agarose into neoagarobiose, neoagarotetraose and neoagarohexaose as the predominant products, as well as a small amount of 3,6-anhydro-α-L-galactose. This is the first to present evidence of agarolytic activity in strain from genus Stenotrophomonas.
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen 361021, China; Research Center of Food Biotechnology of Xiamen City, Xiamen 361021, China; Key Laboratory of Systemic Utilization and In-depth Processing of Economic Seaweed, Xiamen Southern Ocean Technology Center of China, Xiamen 361021, China.
authors.forename: Yanbing
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhao
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen 361021, China; Research Center of Food Biotechnology of Xiamen City, Xiamen 361021, China; Key Laboratory of Systemic Utilization and In-depth Processing of Economic Seaweed, Xiamen Southern Ocean Technology Center of China, Xiamen 361021, China.
authors.forename: Anfeng
authors.initials: A
authors.lastname: Xiao
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen 361021, China; Research Center of Food Biotechnology of Xiamen City, Xiamen 361021, China; Key Laboratory of Systemic Utilization and In-depth Processing of Economic Seaweed, Xiamen Southern Ocean Technology Center of China, Xiamen 361021, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Li
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen 361021, China; Research Center of Food Biotechnology of Xiamen City, Xiamen 361021, China; Key Laboratory of Systemic Utilization and In-depth Processing of Economic Seaweed, Xiamen Southern Ocean Technology Center of China, Xiamen 361021, China.
authors.forename: Zedong
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Department of Food, Nutrition and Package Science, Clemson University, South Carolina 29634, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen 361021, China; Research Center of Food Biotechnology of Xiamen City, Xiamen 361021, China; Key Laboratory of Systemic Utilization and In-depth Processing of Economic Seaweed, Xiamen Southern Ocean Technology Center of China, Xiamen 361021, China. Electronic address: nihui@jmu.edu.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Ni
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006026:Glycoside Hydrolases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008670:Metals / Q000494:pharmacology; D010636:Phenols / Q000737:chemistry / Q000378:metabolism; D011489:Protein Denaturation / Q000187:drug effects; D020588:Stenotrophomonas / Q000201:enzymology* / Q000302:isolation & purification; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D000975:Antioxidants; D004791:Enzyme Inhibitors; D008670:Metals; D010636:Phenols; D006026:Glycoside Hydrolases; C019624:agarase
keywords: Agarase; Antioxidant activity; Characterization; Enzymatic hydrolysates; Stenotrophomonas sp