title: Preparation of glucosamine by hydrolysis of chitosan with commercial α-amylase and glucoamylase.
abstract: OBJECTIVE
  In order to overcome the defects of chemical hydrolysis approach to prepare glucosamine, an enzymatic hydrolysis method was developed.
  
  
  METHODS
  Glucosamine was prepared by hydrolyzing chitosan, employing α-amylase initially, and subsequently, glucoamylase.
  
  
  RESULTS
  The optimal hydrolyzing conditions were as follows: reaction time, 4 h; pH, 5.0; temperature, 50 °C; and, α-amylase, 80 U/g for the initial reaction. Subsequently, glucoamylase was added in the presence of α-amylase. The optimal reaction conditions were found to be: reaction time, 8 h; pH, 4.5; temperature, 55 °C; and, glucoamylase, 4000 U/g. The hydrolysates were subject to filtrating, concentrating to about 20% (w/w), precipitating with five volumes of ethanol, and drying at 60 °C for 2 h. The content and the yield of glucosamine in the dried precipitate were 91.3% (w/w) and 86.2% (w/w), respectively.
  
  
  CONCLUSIONS
  The method developed in this study is a promising option in the preparation of glucosamine.
authors: Jiangsu Key Laboratory of Marine Biotechnology, Huaihai Institute of Technology, Lianyungang 222005, China.
authors: Sai-kun
authors: SK
authors: Pan
authors: Sheng-jun
authors: SJ
authors: Wu
authors: Jin-moon
authors: JM
authors: Kim
mesh_terms: D048271:Chitosan / Q000737:chemistry / Q000378:metabolism*; D005087:Glucan 1,4-alpha-Glucosidase / Q000737:chemistry / Q000378:metabolism*; D005944:Glucosamine / Q000032:analysis / Q000096:biosynthesis*; D006868:Hydrolysis; D000516:alpha-Amylases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D048271:Chitosan; D000516:alpha-Amylases; D005087:Glucan 1,4-alpha-Glucosidase; D005944:Glucosamine