• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.242-243
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• 2004

• Journal of Microbiology and Biotechnology
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• v.19 no.4
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• pp.358-361
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• 2009

The purified endochitosanase(Mw 41 kDa) from bacterium Bacillus cereus D-11 hydrolyzed chitooligomers $(GlcN)_{5-7}$ into chitobiose, chitotriose, and chitotetraose as the final products. The minimal size of the oligosaccharides for enzymatic hydrolysis was a pentamer. To further investigate the cleavage pattern of this enzyme, chitooligosaccharide alcohols were prepared as substrates and the end products of hydrolysis were analyzed by TLC and HPLC. The chitosanase split $(GlcN)_4GlcNOH$ into $(GlcN)_3+(GlcN)_1GlcNOH$, and $(GlcN)_5GIcNOH$ into $(GlcN)_4+(GlcN)_1GlcNOH$ and $(GlcN)_3+(GlcN)_2GlcNOH$. The heptamer $(GlcN)_6GlcNOH$ was split into $(GlcN)_5$ [thereafter hydrolyzed again into $(GlcN_3+(GlcN)2]+(GlcN)_1GlcNOH$, $(GlcN)_4+(GlcN)_2GlcNOH$, and $(GlcN)_3+(GlcN)_3GlcNOH$, whereas $(GlcN)_{1-3}GlcNOH$ was not hydrolyzed. The monomers GlcN and GIcNOH were never detected from the enzyme reaction. These results suggest that D-11 chitosanase recognizes three glucosamine residues in the minus position and simultaneously two residues in the plus position from the cleavage point.

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.345-351
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• 1998

In an effort to develop a potent system for the production of various dp (degree of polymerization) chitooligosaccharides, 32 enzymes or microbial systems were screened for chitosanolytic acitivity using chitosan as a substrate. The efficiency of each enzyme system was evaluated by the changes of turbidity and viscosity of chitosan solution, the amount of precipitate and the reducing sugar-producing activity in the enzymatic reaction mixture. Based on these assay methods for the chitosanase activity, Bacillus sp. P2l out of 32 screened systems showed highly potent endochitosanase, which was comparable with a commercially available enzyme (E7). Chitooligosaccharides of dp 3-7 were separated by TLC as major enzymatic reaction products, suggesting that the chitosanase from Bacillus sp. P2l be endo-splitting type.

• Journal of Animal Science and Technology
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• v.51 no.5
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• pp.387-394
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• 2009

This study was carried out to screen and identify the chitinase and chitosanase producing microorganisms from the feces of calves medicated DFM sincluding chitin in order to do the immune fortification of Korean Native calves. Ten isolates were grown in the medium containing chitin and chitosan that had more than $10^5$ cfu/g in feces. Among these 10 strains, 2 strains (HANDI 110 and HANDI 309) had the chitinase activities and 2 strains (HANWOO and HANYOO) had the chitosanase activities in calves' feces. They showed no reaction in hemolysis tests by utilizing chitin and chitosan. The results from morphological, physicochemical and genetical identification indicated the HANDI 110 as a strain of Escherichia fergusonii, HANDI 309 was identified as a strain of Acinetobacter parvus, HANWOO was identified as a strain of Comamonas koreensis, and HANYOO as a strain of Chryseobacterium indologenes.

• Journal of Microbiology and Biotechnology
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• v.13 no.2
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• pp.269-275
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• 2003

Chitosan-degrading activity induced by chitosan was founf in culture filtrate of Aspergillus flavus IAM2044. Aspergillus flavus IAM2044 had a higher level of chitosanolytic activity when chitosan was used as a carbon source, and yeast extract and peptone were supplemented as nitrogen sources. One of the chitosan-degrading enzymes was purified to homogeneity by ammonium sulfate precipitation followed by cation-exchange and gel filtration chromatographies. The enzyme was monomeric, and its molecular mass was 45 kDa. The optimum pH and temperature of the enzyme were 5.0 and $50^{\circ}C$, respectively. The activity was stable in the pH range of 3.5 to 7.0 and at a temperature below $50^{\circ}C$. Reaction products analyzed by the viscosimetric assay and thin layer chromatography clearly indicated that the enzyme was an exe-type chitosanase, $exo-{\beta}-D-glucosaminidase$, that released GlcN from the nonreducing ends of the oligosaccharide chains.

• Proceedings of the Korean Society of Life Science Conference
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• 2006.09a
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• pp.87.1-87.1
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• 2006

• The Korean Journal of Food And Nutrition
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• v.14 no.6
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• pp.579-584
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• 2001

Chitooligosaccharides were prepared by enzymatic hydrolyzing of crab shell chitosan. Low Molecular Meight chitooligosaccharides(LMW-chitooligosaccharides) , 64.3% of which was composed of trimer, tetramer, and pentamer, was obtained by hydrolyzing chitosan with the chitosanase originated Bacillus pumilus BN -262. High Molecular Meight chitooligosaccharides ( HMW-chitooligosaccharides ) , 49.3% of which was composed of chitooligosaccharides over heptamer, was obtained by hydrolyzing chitosan with the cellulase originated Trichoderma viride. Antimicrobial activity and colony forming inhibitory activity of chitooligosaccharides were tested. MIC of LMW-chitooligosaccharides against Bacillus cereus, Bacillus subtilis, Candida albicans, Escherichia coli, Escherichia coli O157 : H7, Lactobacillus plantarum, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella enteritidis, Salmonella typhimurium, Staphylococcus aureus and Streptococcus mutans was 1.5%, 1.5% above 2.0%, 1.5%, 1.5%, below 0.5%, 2.0%, 1.5%, above 2.0%, 1.0%, 1.5% and 1.0% respectively. .

• The Korean Journal of Mycology
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• v.14 no.4
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• pp.273-280
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• 1986

The degree of autolysis and lytic enzyme production in the culture filtrate of Rhizopus oryzae was investigated. The formation of protoplast by using autolytic enzymes from Rh. oryzae was also attempted. Protoplasts were liberated from Rh. oryzae mycelium by lytic enzymes present in autolytic-phase culture filtrate. Maximum release of chitosanase and proteolytic enzyme into culture filtrate during autolysis was corresponded to maximum protoplast-liberating activity. High yields of protoplasts were obtained from 10 hr-age of Rh. oryzae mycelium with 0.5 M mannitol as osmotic stabilizer. The optimum temperature and pH for mycelium digestion were $25{\sim}30^{\circ}C$ and $6.0{\sim}6.5$ respectively. The mycelium of the 18 hours cultures were treated with autolytic enzyme in same volume of osmotic stabilizer at $30^{\circ}C$ for 5 hours and then it was confirmed by scanning electoron microscope that protoplast were produced beside the digesting cell wall of the fungi.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.608-611
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• 2000

To separate chitosanoligosaccharides easily by size exclusion, an coencapsulating technology of substrate and enzyme was developed. Chitosan and chitosanase were enveloped in this membrane and the product released to medium by size exclusion. The lower limit of the alginate concentration and the agitation speed were 0.5% and 40 rpm, respectively. Membrane thickness and capsules diameter were $10{\mu}m$ and approx. 3.0mm, 1.5mm, respectively. The molecular weight difference by concentration and cps of alginate were of little significance. And also, the molecular weight of distribution according to enzyme concentration was low concentration of enzyme produced high molecular weight of oligosaccharides. At 1.5mm size of capsule, product diffusion rate to outer part was higher than other capsules. The molecular weight distribution of the released oligosaccharides ranged from 1000 to 6000 Da.

• Journal of Microbiology and Biotechnology
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• v.14 no.1
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• pp.41-47
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• 2004

This study was performed to investigate the antimicrobial effects of hetero-chitosans and their oligosaccharides on the halophilic bacterium, Vibrio parahaemolyticus. Nine classes of hetero-chitosan oligosaccharides were prepared based on their molecular weights, using an ultrafiltration membrane reactor system with chitosanase and celluase, from partially different deacetylated chitosans, 90%, 75%, and 50% deacetylated chitosan, respectively. Thirty-two strains of V. parahaemolyticus were isolated from various marine organisms such as shellfish, shrimps, octopus, and seabirds. Seventy-five percent deacetylated chitosan showed the highest antimicrobial acitivity. The minimal inhibitory concentration (MIC) was 0.5 mg/ml on 14 strains of V. parahaemolyticus, and MIC of the rest strains (18 strains) was 1.0 mg/ml. In addition, MIC of most hetero-chitosan oligosaccharides was 8.0 mg/ml. The results revealed that the antimicrobial effects of hetero-chitosans and their oligosaccharides against V. parahaemolyticus depend on the degree of deacetylation, their molecular weights, and strains tested.