Production and Characterization of Extracellular Chitin Deacetylase from Absidia corymbifera DY-9

Recent attention has been paid to the screening of chitin deacetylase (CDA) from fungi, which may be applied into industrial production of chitosan and chitosan oligomers. We screened an extracellular CDA from a fungus that was further identified to be Absidia corymbifera DY-9. CDA from A. corymbifera DY-9 exhibited a higher enzyme activity than that of Mucor rouxii CDA. The highest yield of CDA was achieved in a liquid medium containing 2% powder chitin at pH 9.0, 28 degrees C and 150 rpm. Moreover, the biochemical properties of this enzyme were studied. It was found that the optimal pH and temperature were 6.5 and 55 degrees C. The enzyme activity could be enhanced in the presence of 1-10 mM Co2+, Ca2+ and Mg2+ while inhibited by acetate and EDTA. The enzyme was active on WSCT-50, glycol chitin, chitosan (DDA 71-88 %) and chitin oligosaccharides with a DP no less than 2.