Isolation, characterization and application of a chitosan-degrading fungus from soil.
A chitosan-degrading fungus, BSF114, was isolated from soil. The culture preparation showed strong chitosanolytic enzyme activity at optimum pH 4.0 and optimum temperature of 60 degrees C after 36-40 h fermentation. The rapid decreased viscosity of chitosan solutions at early stage of reaction suggested an endo-type cleavage of the polymeric chitosan chains. To identify the isolated fungus, molecular biological and morphological methods were used. The fungal internal transcribed spacer (ITS) region 1 was amplified, sequenced, and then compared with related sequences in the GenBank database using BLAST. The phylogenetic relationships were then analyzed, and the results showed that the fungus belongs to Aspergillus fumigatus. Morphological observations were also used to confirm the above conclusion. The chitooligosaccharides (COS) obtained through hydrolyzing the colloidal chitosan showed A. fumigatus BSF114 is suitable for degrading chitosan and producing chitooligosaccharides on a large scale. High concentrations of the COS (1000 and 500 microg/mL) significantly proliferated mice marrow cells.
Wei
Xinlin
X
Institute of Food Engineering, College of Life and Environment Science, Shanghai Normal University, 100 Giulin Road, Shanghai, P.R. China. foodlab2010@yahoo.com.cn
Chen
Wei
W
Xiao
Ming
M
Xiao
Jianbo
J
Wang
Yuanfeng
Y
D000818:Animals; D001232:Aspergillus fumigatus / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification* / Q000648:ultrastructure; D001854:Bone Marrow Cells; D049109:Cell Proliferation; D048271:Chitosan / Q000378:metabolism*; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D006026:Glycoside Hydrolases / Q000378:metabolism*; D051379:Mice; D008855:Microscopy, Electron, Scanning; D009844:Oligosaccharides / Q000378:metabolism*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012988:Soil Microbiology
D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer; D009844:Oligosaccharides; D048271:Chitosan; D006026:Glycoside Hydrolases; C019868:chitosanase