• KSBB Journal
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• v.17 no.1
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• pp.100-105
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• 2002

N-acetyl-D-glucosamine oligosaccharides [(GlcNAc)n] whose degree of polymer-ization is from one to ten (n=1-10) were fractionated by column chromatography on CM-Sephadex. Electro dialysis from a partially deacetylated chitosan hydrolysate prepared crudely with the N-acetyl-D-glucosaminidase(chitinase) and exo-N, N'-diacetylchito-biohydrolase(chitobiase) of Serratia marcescens QM B1466. Reducing sugar compositions and sequences of the N-acetyl-glucosamine oligosaccharides were identified by N-acetylation, randomly cleavage with chitinase and ego-splitting with chitobiase. N-acetyl-glucosamine heterochitooligosaccharides with glucosamine oligosaccharides, (GlcN)n at the reducing end residues together with $(GlcN)_1\sim(GlcN)_4$ were detected. Separation was accomplished by prefractionation with election by 0 to 1.0 M NaCl gradient solution. $(GlcNAc)_1 =4.25%,\; (GlcNAc)_2=4.49%,; (GlcNAc)_3=11.1%,\; (GlcNAc)_4=2.5%,$$ $(GlcNAc)_{5}$=0.64%, $(GlcNAc)_{6}$=2.12% and $(GlcNAc)_{7}$=1.21%, respectively, were crystallized after electrodialysis and lyophilization Each N-acetyl-D-glucosamine oligosaccharides content were detected by HPLC.

• Journal of Life Science
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• v.12 no.1
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• pp.77-86
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• 2002

Chitin, a $\beta$-1,4 polymer of N-acetyl-D-glucosamine, is one of the most abundant organic compounds in nature. Chitinase (EC 3.2.1.14) is an enzyme that degrades chitin to chito-oligosaccharides, diacetyl rhitobiose and N-acetyl-D-glucosamine. An extracellular chitinase-producing bacterial strain was isolated from soil and named to as Bacillus subtilis JK-56. Optimum culture condition of B. subtilis JK-56 for the production of chitinase was 1% chitin, 0.5% polypepton, 0.1% KCl, 0.05% MnS $O_4$.4$H_2O$, 37$^{\circ}C$, initial pH 7.0 and 40 hour culture time. When B. subtilis JK-56 was grown in the optimum medium, one major active band and two minor active bands were detected by native-PAGE and active staining of the gel. Among them, the major band was purified from the culture supernatant by 70% ammonium sulfate precipitation and native-PAGE with BIO-RAD Model 491 Prep-Cell and named as Chi-56A. Its molecular weight was estimated to be 53kDa monomer and the isoelectric point (pI) was pH 4.3. The pH and temperature for the optimum activity of Chi-56A were pH 6.0 and $65^{\circ}C$, respectively. Chi-56A was stable up to $65^{\circ}C$ and in alkaline region. Its $K_{m}$ value for colloidal chitin was 17.33g/L. HPLC analysis of the reaction products confirmed that Chi-56A was an exo type chitinase.e.