• Biomedical Science Letters
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• v.24 no.1
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• pp.23-29
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• 2018

Abdominal obesity is considered as one of the most risky factors governing the development of metabolic diseases. Here we identify that human chitinase 3-like 1 (CHI3L1, also called YKL-40 in human) single nucleotide polymorphism (SNP), rs883125, is associated with abdominal obesity in Korean women. Korean women subjects with the rs883125 G/G or C/G genotype present higher waist-hip ratio than subjects with C/C genotype suggesting that human subjects who G nucleotide substitution at the rs883125 tended to more accumulate intra-abdominal fat at the abdominal cavity. In addition, Chi3l1 gene expression is increased in adipose tissue from obese mice and pro-inflammatory cytokine enhances Chi3l1 expression in adipocytes, indicating that Chi3l1 is greatly related with obesity and obesity-induced pro-inflammatory responses. Taken together, the minor allele of rs883125 is associated with a higher prevalence of abdominal obesity in Korean women. These findings suggest that genotype of rs883125 can be a biomarker of incident abdominal obesity and abdominal obesity-related metabolic diseases.

• Research in Plant Disease
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• v.23 no.1
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• pp.19-34
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• 2017

Recent worldwide demand for organic and sustainable agriculture products is driving the development of formulations of biopesticides effective in the field. Biopesticides have the benefit of environmentally-friendly qualities. However, biocontrol approaches largely have been ineffective in controlling plant pests in field conditions. Previously, we developed a cost-effective biocontrol formulation containing chitin and chitinase-producing biocontrol bacteria with field efficacy. This formulated product has successfully suppressed various plant diseases in the field conditions. In this review, we focus on ecological aspects and the potential mechanisms underpinning the success of chitinase-producing bacteria. In addition, we discuss the possibility on-site cultivation of the formulated products to further strengthen the approach as being farmer friendly and successful.

• Journal of Microbiology and Biotechnology
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• v.22 no.10
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• pp.1359-1366
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• 2012

A strain of Streptomyces cavourensis subsp. cavourensis (coded as SY224) antagonistic to Colletotrichum gloeosporioides infecting pepper plants was isolated. SY224 produced lytic enzymes such as chitinase, ${\beta}$-1,3-glucanase, lipase, and protease in respective assays. To examine for antifungal activity, the treatments amended with the nonsterilized supernatant resulted in the highest growth inhibition rate of about 92.9% and 87.4% at concentrations of 30% and 10%, respectively. However, the sterilized treatments (autoclaved or chloroform treated) gave a lowered but significant inhibitory effect of about 63.4% and 62.6% for the 10% supernatant concentration, and 75.2% and 74.8% for the of 30% supernatant concentration in the PDA agar medium, respectively, indicative of the role of a non-protein, heat stable compound on the overall effect. This antifungal compound, which inhibited spore germination and altered hyphal morphology, was extracted by EtOAc and purified by ODS, silica gel, Sephadex LH-20 column, and HPLC, where an active fraction was confirmed to be 2-furancarboxaldehyde by GS-CI MS techniques. These results suggested that SY224 had a high potential in the biocontrol of anthracnose in pepper, mainly due to a combined effect of lytic enzymes and a non-protein, heat-stable antifungal compound, 2-furancarboxaldehyde.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.346-356
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• 2011

BACKGROUND: Chemical fungicides not only may pollute the ecosystem but also can be environmentally hazardous, as the chemicals accumulate in soil. Biological control is a frequently-used environment-friendly alternative to chemical pesticides in phytopathogen management. However, the use of microbial products as fungicides has limitations. This study isolated and characterized a three-antifungal-enzyme (chitinase, cellulase, and ${\beta}$-1,3-glucanase)-producing bacterium, and examined the conditions required to optimize the production of the antifungal enzymes. METHOD AND RESULTS: The antifungal enzymes chitinase, cellulase, and ${\beta}$-1,3-glucanase were produced by bacteria isolated from an sawmill in Korea. Based on the 16S ribosomal DNA sequence analysis, the bacterial strain AM50 was identical to Streptomyces sp. And their antifungal activity was optimized when Streptomyces sp. AM50 was grown aerobically in a medium composed of 0.4% chitin, 0.4% starch, 0.2% ammonium sulfate, 0.11% $Na_2HPO_4$, 0.07% $KH_2PO_4$, 0.0001% $MgSO_4$, and 0.0001% $MnSO_4$ at $30^{\circ}C$. A culture broth of Streptomyces sp. AM50 showed antifungal activity towards the hyphae of plant pathogenic fungi, including hyphae swelling and lysis in P. capsici, factors that may contribute to its suppression of plant pathogenic fungi. CONCLUSION(S): This study demonstrated the multiantifungal enzyme production by Streptomyces sp. AM50 for the biological control of major plant pathogens. Further studies will investigate the synergistic effect, to the growth regulations by biogenic amines and antifungal enzyme gene promoter.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.2
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• pp.129-134
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• 1988

Enzymatical properties of Streptomyces sp. S-45 producing chitinase and ${\beta}$-1.3-glucanase isolated from soil were investigated. Chitinase activity was 3.01(U/ml) and ${\beta}$-1.3-glucanase activity was 2.49(U/ml). The optimum medium for mycolytic enzyme production of strain was composed of 0.7% colloidal chitin, 0.3% glucose, 0.5% asparagine, 0.2% peptone, 0.01% NaCl, 0.01% $K_2HPO_4$ and 0.01% $MgSO_4{\cdot}7H_2O$ in intial pH 7.0. The optimal condition for mycolytic enzyme activities were: pH 6.5-7.0, $45-50^{\circ}C$. Enzyme activities were activated by metal ion as $10^{-2}M\;Co^{{+}{+}}$, $Cu^{{+}{+}}$, $Mn^{{+}{+}}$, $Al^{{+}{+}{+}}$ and $10^{-3}M\;Sn^{{+}{+}}$ but $Ag^{{+}{+}}$, $Hg^{{+}{+}}$ inhibited.

• Korean Journal of Environmental Biology
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• v.20 no.2
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• pp.130-135
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• 2002

Species of Genus Trichoderma are commercially applied as biological control agents against fungal Pathogens. A powerful biocontrol agent, Trichoderma sp. SJG-99721 was isolated from 305 isolates by morphological characters, chitinase activities and antifungal activities against Phytophthora capsiei. The isolate was identified as Trichoderma harzianum from various features such as growth rate at $27^\circ{C}$, significant growth ratio of $27^\circ{C}$ to $17^\circ{C}$, amount of aerial mycelium, types of branching: system, and disposition patterns of phialide and phialospore. Trichoderma harzianum SJG-99721 have been shown to act as a powerful biological agent against fungal phytopathogens; Botrytis cinerea, Rhizoctonia solani, Phytophthora cryptogea, Phytophthora capsiei, Sclerotinia sclerotiorum, Mycoshaerella melonis, Alternaria sotani, Fusarium oxysporum, Collectotrichum gloesporioodes, Alternaria alternata, Phythium ultimum, Phytophthora drechsleri, Pyricularia grisea.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.492-500
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• 2015

Our previous report demonstrated successful isolation of soil-borne bacteria that suppressed the potential of Rhizoctonia solani AG2-2 (IV) causing turfgrass large patch disease when applied to Korean lawngrass (Zoysia japonica). The current study aimed to uncover the mechanisms of this antagonism of Rhizoctonia solani and to define culture conditions for the isolated microbes. We found that two Bacillus isolates, I-009 and FRIN-001-1 strains, produced cellulase and siderophore, but not chitinase, while the Pseudomonas YPIN-022 strain was found to release only siderophore, implying that three antagonistic bacteria commonly interrupt Fe uptake by the large patch pathogen. The I-009 and FRIN-001-1 isolates grew best at 35 and $30^{\circ}C$ in growth medium of pH 5 to 8 for 32 and 28 h, respectively, while optimum growth for the YPIN-022 strain was found at $35^{\circ}C$ at pH 5 to 9 for 24 h. Good growth of I-009 and YPIN-022 over 24 h was obtained in M9 minimal medium supplemented with 1% sucrose, 0.5% yeast extract and 0.1% potassium chloride. FRIN-001-1 grew well in M9 medium with 1% mannitol, 0.5% yeast extract and 0.1% potassium phosphate dibasic.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.244-250
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• 1996

The objectives of this paper were to study the existence of resistant substance to pine gall midge from needles of Pinus densiflora, P. thunbergii, P. virginiana, and P. thunbergii${\times}$P. virginiana, and also to investigat whether terpenoids, fragrant substance contained in those species seduce or evade imago of pine gall midge to oviposit. Also, terpenoids and phenolic compounds were bioassayed on larva. The results are follows. Adults of pine gall midge oviposited indiscriminately all investigated pine species, while gall formation rate by pine gall midge showed 0% in Pinus virginiana, 9% in P. thunbergii${\times}$P. virginiana, 22% in P. thunbergii. It is suggested that young larvae is necrotized by resistant substance in the needles of P. virginiana. This results might mean that fragrant substance, terpenoids, extracted from pine species is not seducible or evadable substance. Larvae of pine gall midge placed on terpenoid and resin were not necrotized. The necrosis rate of larvae of pine gall midge cultivated in the solution of phenolic compounds extracted from needles of P. virginiana, salicylic acid and chitinase showed 89, 92, and 86% respectively. And necrosis rate was 56 and 59% in phenolic compounds extracted from P. densiflora and gallic acid respectively. So, it is postulated that phenolic compounds contained in needles of P. virginiana, salicylic acid and chitinase are resistant substance to pine gall midge.

• 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.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.1
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• pp.15-20
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• 2006

Biological control by chitinolytic microorganisms is being evaluated as management options for soilborne diseases. Forty kilograms of chitin compost (CTC) and control compost (CC) were amended on tomato plots ($15m{\times}0.5m$) 7 d before transplanting to evaluate enzymatic activities and the control of Fusarium wilt. Samples were taken on day 1, 3, 5, and 7, the day 1 corresponded to the 66 d after transplanting, the day on which the initial wilting symptoms occurred in plants of CC treated plots. The chitinase activity in soil of CTC was always higher compared to the control. Pathogenesis related (PR) protein (chitinase, ${\beta}$-1, 3-glucanase and peroxidase) activities in tomato roots in CC increased every day and showed marked differences compared to CTC. Wilting symptoms (96 d after transplanting) were reduced by 25% in CTC compared to the control. Protection of tomato plant may be correlated with the high levels of soil enzyme activities resulting from the chitin compost.