• Journal of Applied Biological Chemistry
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• v.61 no.3
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• pp.233-238
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• 2018

Chitinases are glycosyl hydrolases which cleave the ${\beta}$-1,4 linkage of chitin into oligo or monomers of N-acetylglucosamine. These bacterial enzymes have been used for a wide range of applications in the food and pharmaceutical industries. In this study, we isolated two potential chitinolytic strains, BAO-01 and BAO-02, from salt-fermented shrimp, which were shown to belong to the genus Salinivibrio through genetic characterization using 16S rRNA. These isolates were gram-positive, rod-shaped, and non-spore forming. BAO-01 showed greater growth and chitinase activity than BAO-02 after the incubation at $37^{\circ}C$ for 4 days. Both strains grew on a wide range of carbon and nitrogen sources, pH values, temperatures, and salt levels. However, they showed minor biochemical differences. In addition, their antimicrobial activities against foodborne pathogens and antibiotic susceptibilities were evaluated. These Salinivibrio spp. did not show bioamine production, hemolytic activity, and mucin degradation. Therefore, the in vitro screening results suggested that these bacteria could be widely used as new candidates for chitin hydrolyzation and seafood fermentation.

• Journal of Microbiology and Biotechnology
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• v.11 no.1
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• pp.72-78
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• 2001

It is possible ot prepare protoplasts of the zygomycete fungus, Phycomyces blakesleeanus, by digesting the cell wall of spore germlings with commercially available chitinase and chitosanase. However, the cells without any cell walls immediately form large aggregates, and thus, it is difficult to isolate the individually separated protoplasts. Inherent problem with the formation of aggregates in preparing protoplasts could be solved by the use of bovine serum albumin (BSA). As a result, we were able to prepare a large number of single protoplsts quickly and easily. We took time-lapse photomicrographs of the formation of protoplasts, and found that there were certain regions of the cell wall of spore germlings that were sensitive to chitinase and chitosanase, although the cell wall of the original spores is known to be insensitive to these enzymes. There are two kinds of cell walls on a spore germling; one with a bound wheat germ agglutinin (WGA), and the other a bound concanavalin A (ConA). Furthermore, only cells with walls which had bound WGA were able to regenerate, while those with walls with bound ConA were not able to regenerate.

• Journal of Microbiology
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• v.33 no.4
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• pp.295-301
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• 1995

An antifungal Pseudomonas stutzeri YPL-1 produced extracellular chitinase and .betha.-1, 3-glucanase that were key enzymes in the decomposition of fungal hyphal walls. These lytic extracellular enzymes markedly inhibited mycelial growth of the phytopathogenic fungus Fusarium solani. A chitinase from P. stutzeri YPL-1 inhibited fungal mycelial growth by 87%, whereas a .betha.-1, 3-glucanase from the bacterium inhibited growth by 53%. Furthermore, co-operative action of the enzymes synergistically inhibited 95% of the fungal growth. The lytic enzymes caused absnormal swelling and retreating on the fungal hyphal walls in a dual cultures. Scanning electron microscopy clearly showed hyphal degradation of F. solani in the regions interacting with P. stutzeri YPL-1. In an in vivo pot test, P. stutzeri YPL-1 proved to have biocontrol ability as a powerful agent in controlling plant disease. Planting of kidney bean (Phaseolus vulgaris L.) seedlings with the bacterial suspension in F. solani-infested soil significantly suppressed the development of fusarial root-rot. The characteristics of a crude preparation of .betha.-1, 3-glucanase produced from P. stutzeri YPL-1 were investigated. The bacterium detected after 2 hr of incubation. The enzyme had optimum temperature and pH of 40.deg.C and pH 5.5, respectively. The enzyme was stable in the pH range of 4.5 to 7.0 and at temperatures below 40.deg.C, with a half-life of 40 min at 60.deg.C.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.95-99
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• 1995

We have previously established a system for plant regeneration through somatic embryogenesis and Agrobacterium-mediated transformation of Korean ginseng. In this study to produce a fungus-resistant plant, we introduced a bean chitinase gene into ginseng using the transformation system. A binary vector pChi/748 was constructed by introducing the bean basic chitinase gene into EcoRI site of pGA748 which carries the CaMV 35S promoter governing the introduced gene and neomycin phosphotransferase II(NPT-II)gene as a positive selection marker. Cotyledonary explants were cocultured with A. tumefaciens strain LBA4404 harboring the binary vertor pChi/748 for 48 h, and transferred to MS medium supplemented with l mg/L2,4-D,0.1mg/L kinetin, 100 mg/L kanamycin, and 500mg/L carbenicillin. Kanamycin-resistant calli were formed on the cut surface of cotyledonary explants after one month of culture, and subsequently they gave rise to somatic embryos. Upon transfer onto medium containing 1 mg/L each of BA and GA$_3$, most of them converted to plantlets after 5 weeks of culture. The genomic DNA of eight kanamycin-resistant regenerants was subjected to polymerase chain reaction (PCR) using two specific 21-mer oligonucleotides derived from the chitinase gene. PCR-Southern blot analysis confirmed that the chitinase gene was incorporated into six out of the eight regenerants..

• Korean Journal of Microbiology
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• v.41 no.4
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• pp.293-299
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• 2005

Many isolates from soil of Korean ginseng rhizosphere did not show remarkable growth on full strength of the conventional nutrient broth (NB medium) but grew on its 100-fold dilution (DNB medium). Six hundred-forty strains were isolated as oligotrophic bacteria. In the course of screening for new bioactive compounds from oligotrophic bacteria from soil, 8 strains which had appeared to form of clear zone on a medium containing colloidal chitin as a sole carbon source were selected for further studies. Strain CR42 hydrolyzed a fluorogenic analogue of chitin, 4-methylumbelliferyl-D-glucosaminide (MUF-NAG) . Mo st of the culture supernatant of these isolates hydrolyzed 4-methylumbelliferyl-D-N,N'-diacetylchitobioside (MUF-diNAG). The isolates were heterogeneous and categorized to gamma- and beta-proteobacteria, Bacillaceae, Actinobactepia, and Bacteroides by 16S rRNA analysis. Two strains, WR164 and CR18, had a 16S rRNA sequence of $95-96\%$ identical to uncultured bacteria. It was observed that CR2 and CR75 could inhibit the growth of Colletotrichum gloeosporioides with hyphal extention-inhibition assay on PDA plate supplemented with $1\%$ colloidal chitin.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.3
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• pp.148-155
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• 2023

This study was aimed to isolate bacterial inoculants producing chitinase and evaluate their application effects on corn silage. Four corn silages were collected from four beef cattle farms to serve as the sources of bacterial inoculants. All isolates were tested against Fusarium graminearum head blight fungus MHGNU F132 to confirm their antifungal effects. The enzyme activities (carboxylesterase and chitinase) were also measured to isolate the bacterial inoculant. Based on the activities of anti-head blight fungus, carboxylesterase, and chitinase, L. buchneri L11-1 and L. paracasei L9-3 were subjected to silage production. Corn forage (cv. Gwangpyeongok) was ensiled into a 10 L mini silo (5 kg) in quadruplication for 90 days. A 2 × 2 factorial design consists of F. graminearum contamination at 1.010⁴ cfu/g (UCT (no contamination) vs. CT (contamination)) and inoculant application at 2.1 × 10⁵ cfu/g (CON (no inoculant) vs. INO (inoculant)) used in this study. After 90 days of ensiling, the contents of CP, NDF, and ADF increased (p<0.05) by F. graminearum contamination, while IVDMD, acetate, and aerobic stability decreased (p<0.05). Meanwhile, aerobic stability decreased (p<0.05) by inoculant application. There were interaction effects (p<0.05) on IVNDFD, NH3-N, LAB, and yeast, which were highest in UCT-INO, UCT-CON, CT-INO, and CT-CON & INO, respectively. In conclusion, this study found that mold contamination could negatively impact silage quality, but isolated inoculants had limited effects on IVNDFD and yeast.

• Proceedings of the Plant Resources Society of Korea Conference
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• 1997.10b
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• pp.51-51
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• 1997

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1998.06a
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• pp.369.1-370
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• 1998

• The Plant Pathology Journal
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• v.17 no.6
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• pp.365.2-365
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• 2001

• Proceedings of the Korean Society of Life Science Conference
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• 2005.09a
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• pp.98-98
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• 2005