• Microbiology and Biotechnology Letters
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• v.7 no.3
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• pp.149-155
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• 1979

Streptomyces sp. 115-5 was selected as the most active microorganism of about 200 strains for the production of chitinase. The enzyme was purified by (NH$_4$)$_2$SO$_4$ treatment, 1st-Sephadex G-100, DEAE-Cellulose, 2nd-Sephadex G-100 column chromatography, and evidence for homogenity was obtained from CM-Sephadex C-50 column chromatography and polyacylamide gel electrophoresis. The purified enzyme hydrolyzed chitin (N-acetyl glucosamine polymer) and chitosan (glucosamine polymer) but not cellulose. And with chitin as the substrate, a Km value of 3.6 mg of chitin per ml and a Vmax of 100 $\mu$mo1e fer hr were found. The activation of the chitinase was 3.66 kcal per mole. The molecular weight of the enzyme was esti-mated about 56,000 daltons by Sephadex G-100 chromatography and isoelectric point as pH 3.0.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.18-24
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• 2001

The advantage of using Streptomyces griseus HUT 6037 in the production of chitinase or chitosanase is that the organism is capable of hydrolyzing amorphous or crystalline chitin and chitosan according to the type of the substrate used. We investigated the effects of the enzyme induction time and chitin sources, CM-chitosan and deacetylated chitosan (degree of deacetylation 75-99%), on production of chitosanase. We found that this strain accumulated chitosanase when cells were grown in the culture medium containing chitosanaceous substrates instead of chitinaceous substrates. The highest chitosanase activity was obtained at 4 dyas of cultivation with 99% deacetylated chitosan. The specific activities of chitinase and chitosanase were 0.91 and 1.33 U/mg protein at 3 and 5 days, respectively. From the study of the enzymatic digestibility of various degrees of deacetylated chitosan, it was found that (GlcN)$_3$, (GlcN)$_4$and (GlcN)(sub)5 were produced during the enzymatic hydrolysis reaction. The results of this study suggested that the sugar composition of (GlcN)$_3$was homogeneous and those of (GlcN)$_4$and (GlcN)(sub)5 were heterogeneous.

• Microbiology and Biotechnology Letters
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• v.24 no.5
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• pp.567-573
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• 1996

Chitinase (EC 3.2.1.14) from culture fluid of Bacillus licheniformis KFB-C14 was purified 66-folds to homogenity in overall yield of 21% by ammonium sulfate fractionation, DEAE-Toyopearl, Butyl-Toyopearl and TSK-Gel HW-55F column chromatography. The enzyme protein had a molecular weight of about 86,000 and was composed of one subunit. The enzyme was significantly stable not only at high temperature but also on treatment with organic solvents and protein denaturants such as SDS, urea and guanidine-HC1. The optimum temperature and pH for reaction was 60$\circ $C and 6.0, respectively. The enzyme activity was inhibited by only Mn$^{2+}$ ion, but not inhibited by EDTA, N- ethylmaleimide and pCMB. The enzyme had high activity with colloidal chitin (V$_{max}$: 421) and commercial chitin (V$_{max}$: 480), but not with typical substrates of exo type chitinase. The thermostable chitinase had an useful reactivity for producing functional chitooligosaccharide, showing the production of (GlcNAc)$_{1}, (GlcNAc)$_{3}$, and (GlcNAc)$_{2}$ as major product.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.151-158
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• 1997

For the production of potent chitinolytic enzyme from bacteria, screening was carried out. Of 100 samples from soil, fresh water and sea water collected from the Kyung-gi area, 7 strains of chitinolytic bacteria were isolated. Among them, Aeromonas hydrophila 5-3K showed the highest chitinolytic activity. Culture conditions of Aeromonas hydrophila for the production of chitinolytic enzyme were inverstigated and lytic enzyme was fractionated by the use of ammonium sulfate and Sephadex G-100. Maximum production of chitinolytic enzyme was obtained at pH 7.0 and 30$\circ$C with chitin concentration between 0.2% and 1.0%. Conditions for the enzyme production were optimized including fermentor cultivation. The chitinolytic system of Aeromonas hydrophila 5-3K was composed of two enzymes, chitinase and chitobiase.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.3
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• pp.303-307
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• 1996

The degree of autolysis and presence of cell-wall degrading enzymes in an anaerobic ruminal fungus, Piromyces communis OTSI, grown in liquid medium, was monitored to evaluate the effect of self-digestion on fungal biomass. After a 30 days incubation period fungal dry weight decreased by 45% and the cell wall component chitin decreased by 22%. Chitinase activity detected in the supernatant was mainly of the endotype and peaked at day 6 of the incubation. ${\beta}-1$, 3-glucanase was detected from day 4 and increased throughout the incubation period. Autolysis was a slow process, and under natural conditions it is unlikely that it plays a significant role in the degradation of the spent fungal vegetative stage in the rumen.

• Journal of Microbiology and Biotechnology
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• v.5 no.2
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• pp.80-86
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• 1995

The bacterial strain WC-17 able to produce chitinase was isolated from soil using an enrichment technique. The isolated strain was identified as Acinetobacter sp. judging by their morphological and physiological characterisitics. The optimal culture conditions for the production of chitinase of Acinetobacter sp. WC -17 are 1.5% colloidal chitin and 1 % tryptone at $30^{\circ}C$ with pH 6.5. Since the enzyme was rapidly produced in a culture supplied with chitin, glucose, or N-acetylglucosamine but not with other polymers and monosaccharide, the enzyme was considered to be an inducible enzyme. Notably N- acetylglucosamine and glucose were found to be effective inducers at low concentrations but repressors at excessive concentrations. The cultural supernatant of Acinetobacter sp. WC-17 inhibited the growth of phytopathogenic fungi such as P.oryzae, R.solani, and F.solani. Among the phytopathogenic fungi tested, P.oryzae was the most sensitive. The conventional agar plate (PDA containing 1 % colloidal chitin) method also produced the same result.

• Microbiology and Biotechnology Letters
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• v.6 no.4
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• pp.149-153
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• 1978

A strain of Streptomyces sp producing chitinase was isolated from soil and its cultural condition and some properties of this enzyme were investigated. When 0.375 per cent of glucose was added to basal medium, this organism produced the most quantities of this enzyme after shaking culture at 3$0^{\circ}C$ for 48 hrs., while the production of the enzyme was repressed at the more concentration of glucose than that. The enzyme had a optimal pH of 7.0, optimal temperature of 5$0^{\circ}C$ and the activity of that was not decreased by heat treatment for 20 minute at 7$0^{\circ}C$. And then the activity was increased by Co$^{2+}$ but was slightly inhibited by Hg$^{2+}$, Ni$^{2+}$, Pb$^{2+}$.EX> 2+/.

• Korean Journal of Microbiology
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• v.38 no.1
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• pp.50-53
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• 2002

The optimum temperature and pH for mycelial growth of B. bassiana DGUM 34001 were $24^{\circ}C$ and pH 7.0, respectively. Among the complex media used, mushroom complex medium (MCM) was the most favorable for mycelial growth. When Czapek-Dox medium was used as a minimal medium, glucose was an excellent source for carbon and energy. Soytone and sodium phosphate were favorable constituent for culture medium as a source of organic nitrogen and phosphorus, respectively. When the fungus was grown in MCM broth, the specific activity of extracellular enzyme of ${\alpha}$-amylase, lipase, chitinase, CMCase and pretease were 297.0, 0.058, 0.33, 0.21 and 22.8 units/mg protein, respectively. When various sources of organic nitrogen and chitin were supplemented to determine the production of enzymes, casein and soluble chitosan enhanced the production of extracellular protease and chitinase.

• Applied Biological Chemistry
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• v.34 no.1
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• pp.54-60
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• 1991

Serratia marcescens CK-3, decomposing chitin which is a mar component of cell wall in phyitopathogenic fungi, was isolated from the continuous cropping rhizosphere of pepper and cucumber and its enzymatic property was examined. S. marcescens CK-3 was found tn have an tagonistic effects against, Fusarium axysporum and Rhizoctonia solani and to have complex enzyme system such as chitinase, laminarinase, and proteinase. The preferable composition of the medium for production of chitinase was fond and was as follows : colloidal chitin 1.5%, tryptone 0.5%, glucose 1.0%, peptone 0.2%, $MgSO_4{\cdot}7H_2O\;0.1%,\;K_2HPO_4\;0.1%,\;and\;NaCl\;0.1%$(w/v), pH 6.8. The maximum enzyme production was observed after culture of 72 hours at $30^{\circ}C$ using a medium containing the above chemical composition. The optimal pH and temperature for in vitro activity of chitinase from S. marcescens CK-3 were pH 7.5 and $50^{\circ}C$, respectively. The enzyme activity in-creased by metal ions such as$Ag^+$ and $Mn^{++}$.