• Journal of Microbiology and Biotechnology
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• v.20 no.8
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• pp.1179-1184
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• 2010

We report the generation of the first monoclonal antibody that specifically binds to the polysaccharide chitosan. Mice were immunized with a mixture of chitosans, and hybridoma clones were screened for specific binders, resulting in the isolation of a single clone secreting a chitosan-specific IgM, mAbG7. In ELISAs, the antibody could bind to chitosans of varying composition, but demonstrated the highest affinity for chitosans with lower degrees of acetylation (DA) and very poor binding to chitin. We tested the ability of the antibody to bind to chitosan in situ, using preparations of fungal cell walls. Immunofluorescence microscopy confirmed that the antibody bound strongly to the cell walls of fungi with high levels of chitosan, whereas poor staining was observed in those species with cell walls of predominantly chitin or cellulose. The potential use of this antibody for the detection of fungal contamination and the protection of plants against fungal pathogens is discussed.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.839-846
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• 1999

An extracellular chitinase-producing bacterial strain induced by colloidal chitin was isolated from sea sand and was identified to be a member of the genus Cytophaga. The chitinase was purified successively by 30-60% ammonium sulfate fractionation, and DEAE-Bio gel A column, Octyl-Sepharose CL-4B column, and DEAE-Bio gel A column chromatographies. The enzyme had a molecular mass of 59.75 kDa, and the amino terminal amino acid sequence was ATPNAPVISW MPTDXXLQNXS. The enzyme acted better on colloidal chitin as a substrate than on chitosan. For colloidal chitin and chitosan (Degree of Acetylation, 15-25%), $K_{cat}$ values were 0.60U/mg and 0.08U/mg, respectively. HPLC analysis of the enzymatic reaction products showed that the chitinase produced mostly N-acetyl-D-glucosarnine and di-N-acetylchitobiose. The optimum temperature and pH for the enzyme were $50^{\circ}C$ and 4.0, respectively. N-Bromosuccinimide and $Hg^{2+}$ inhibited the chitinase activity as much as 90%, and $Sb^{3+}$, diethylpyrocarbonate, and $Ag^{+}$ inhibited it by 50-70%.