Tuesday, May 3, 2011
A chitin-degrading microorganism, Chitinibacter tainanensis, was identified in a soil sample from southern Taiwan. The final product of chitin degradation is white crystal N-acetyl glucosamine by the microbe. The purity of N-acetyl glucosamine can reach more than 99% after the reaction mixture of chitin digestion concentrated and crystallization. In addition, the biotransformation yield is also impressive. N-acetyl glucosamine of 0.98 g can be obtained with 1 g substrate, β-chitin. Though, the yield is only 0.75 g/g by the substrate of α-chitin.
The mechanism of degradation was also investigated. Both endochitinase and N-acetylglucosaminidase activities were detected in membrane parts of C. tainanensis. However, N-acetylglucosaminidase expressed much higher activity than endochitinase did. The optimum pH for chitin degradation was determined at 7.0. But it is noted that the optimum pH for N-acetyl glucosamine production was 5.3. These results implied that some molecules with enzyme activity in addition to N-acetylglucosaminidase play crucial roles for chitin degradation.