Purification of Aspergillus sp. S1-13 chitinases and their role in saccharification of chitin in mash of solid-state culture with shellfish waste

J Biosci Bioeng. 2007 Jun;103(6):535-41. doi: 10.1263/jbb.103.535.

Abstract

In a suspension of solid-state culture of Aspergillus sp. S1-13 containing a lactic acid-treated crab shell as the substrate, the saccharification of chitin in the shell proceeded to form N-acetylglucosamine (GlcNAc): the culture was the source of chitin and chitinases. The analysis of chitinases in the water-extract of the solid-state culture indicated occurrence of an exochitinase (Exo, MW 73 kDa) and two endochitinases. The amounts of the endochitinases suggested that one of them (Endo-1, MW 45 kDa) might be the main species in the chitin-saccharification. The amount of GlcNAc released from the LA-treated crab shell by the combined action of isolated Exo and Endo-1 was very small, predicting participation in the saccharification of other enzyme species, which might be hardly extracted with water from the solid-state culture. The re-extraction of the solid-state culture using 2 M KCl, which was extracted with water beforehand, demonstrated another endochitinase (Endo-2, MW 51 kDa). Endo-2 isolated from the salt-extract can adsorb to chitin, and can hydrolyze the chitin in the adsorbed state. The roles of these chitinases in the chitin-saccharification based on their properties and combined action were discussed.

MeSH terms

  • Acetylglucosamine / metabolism
  • Animals
  • Aspergillus / enzymology*
  • Aspergillus / metabolism
  • Biodegradation, Environmental
  • Chitin / metabolism*
  • Chitinases / isolation & purification*
  • Chitinases / metabolism*
  • Hydrogen-Ion Concentration
  • Hydrolysis
  • Molecular Weight
  • Refuse Disposal
  • Shellfish
  • Temperature
  • Waste Products

Substances

  • Waste Products
  • Chitin
  • Chitinases
  • Acetylglucosamine