• Applied Biological Chemistry
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• 제35권3호
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• pp.191-195
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• 1992

강낭콩 잎에서 에틸랜에 의하여 유도되는 분자량 30KD인 염기성 키틴분해효소를 정제하고 그 항균활성을 연구하였다. 이 단백질은 chitinase 활성과 lysozyme 활성을 가졌으며, Aspergillus fumigatus, Botrytis cinerea, Fusarium oxysporum, Rhizoctonia solani의 균사 생장을 억제하였다. 그러나 함께 실험한 2종류의 미생물 chitinase, 달걀 lysozyme, 파파야 protease는 이들에 대한 항균작용을 갖지 않았다. 이상의 결과는 lysozyme 활성을 가진 식물 chitinase가 병원균의 균사생장을 억제하여 자신을 방어할 수 있음을 시사한다.

• 한국식품영양과학회지
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• 제30권4호
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• pp.760-763
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• 2001

시판되는 새우젓의 새로운 기능성 지표를 제시하고자 단백분해효소의 활성 및 키토산 분해활성 등을 측정하였다. 시판 되는 새우젓의 염도를 측정한 결과. 29.8~48.3%로 제품에 따라 최대 19% 정도의 염도 차이를 보였다. 총질소량은 3510.5 ~7314.1 mg/100g 으로 A시료가 7314.1 mg/100 g으로 가장 높은 총질소 함량을 보인 반면 D 시료는 3510.5 mg/100 g으로 비교적 낮은 총질소 함량을 보였다. 아미노태 질소량은 321.2~723.9 mg/100g으로 총질소 함량이 가장 낮았던 D시료가 아미노태 질소 함량이 낮았다. 5개 시판 새우젓의 평균 펩타이드 길이(average peptide length: APL)는 10.1~15.0이었다. 휘발성 염기질소는 14.1~98.6mg/100g 으로 D시료에서 가장 높은 98.6mg%의 함량을 보였다. 단백질 분해효소 활성은 18~232 unit로 차이를 보이고 있으며 C번 시료의 단백질 분해 효소 활성이 232 unit로 가장 높은 효소활성을 보였다. Chitinase 활성은 14.4~171 unit의 활성을 보였으며 E번 새우젓이 171 unit로 가장 높은 효소 활성을 보였다.

• 미생물학회지
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• 제40권3호
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• pp.230-231
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• 2004

꽃송이버섯(Sparassis crispa DSMZ 5201)의 균사를 사용하여 균사외 효소활성을 측정하였다. Yeast-malt extract-glucose 배지를 사용하여 $24^{\circ}C$에서 15일간 배양 후 배양여액을 조효소원으로 사용하였을 때, $\alpha$-amylase효소의 활성은 44.27 unit/$mg{\cdot}protein$이었다. 배양여액 중의 Protease, CMCase, $\beta$-glucosidase, chitinase 및 exo-$\beta$-1,4-glucanase의 세포외 효소활성은 상대적으로 높았으나, xylanase 효소활성은 낮게 나타났다.

• Journal of Microbiology and Biotechnology
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• 제20권6호
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• pp.1001-1005
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• 2010

The chitinase-producing strain TKU008 was isolated from soil in Taiwan, and it was identified as a new species of Pseudomonas. The culture condition suitable for production of chitinase was found to be shaking at $30^{\circ}C$ for 4 days in 100 ml of medium containing 1% shrimp and crab shell powder, 0.1% $K_2HPO_4$, and 0.05% $MgSO_4{\cdot}7H_2O$ (pH 7). The TKU008 chitinase was suppressed by the simultaneously existing protease, which also showed the maximum activity at the fourth day of incubation. The molecular mass of the chitinase was estimated to be 40 kDa by SDS-PAGE. The optimum pH, optimum temperature, pH stability, and thermal stability of the chitinase were pH 7, $50^{\circ}C$, pH 6-7, and <$50^{\circ}C$, respectively. The chitinase was completely inhibited by $Mn^{2+}$ and $Cu^{2+}$. The results of peptide mass mapping showed that 11 tryptic peptides of the chitinase were identical to the chitinase CW from Bacillus cereus (GenBank Accession No. gi 45827175) with a 32% sequence coverage.

• Mycobiology
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• 제45권4호
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• pp.385-391
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• 2017

The ability of Bacillus subtilis, strain ALICA to produce three mycolytic enzymes (chitinase, ${\beta}$-1,3-glucanase, and protease), was carried out by the chemical standard methods. Bacillus subtilis ALICA was screened based on their antifungal activity in dual plate assay and cell-free culture filtrate (25%) against five different phytopathogenic fungi Alternaria alternata, Macrophomina sp., Colletotrichum gloeosporioides, Botrytis cinerea, and Sclerotium rolfesii. The B. subtilis ALICA detected positive for chitinase, ${\beta}$-1,3-glucanase and protease enzymes. Fungal growth inhibition by both strain ALICA and its cell-free culture filtrate ranged from 51.36% to 86.3% and 38.43% to 68.6%, respectively. Moreover, hyphal morphological changes like damage, broken, swelling, distortions abnormal morphology were observed. Genes expression of protease, ${\beta}$-1,3-glucanase, and lipopeptides (subtilosin and subtilisin) were confirmed their presence in the supernatant of strain ALICA. Our findings indicated that strain ALICA provided a broad spectrum of antifungal activities against various phytopathogenic fungi and may be a potential effective alternative to chemical fungicides.

• 한국균학회지
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• 제51권4호
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• pp.265-276
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• 2023

본 연구는 담수 환경에서 분리한 곰팡이의 특성을 알아보기 위해 효소 활성을 평가하였다. 40개의 곰팡이들은 다양한 담수 시료로부터 분리되었으며, 계통분석을 통해 동정하였다. 실험에 사용된 균주들은 최근에 국내에 보고되었거나, 아직 보고되지 않은 종으로서 이에 대한 특성 정보가 거의 알려지지 않았다. 본연구에서는 40개 균주를 대상으로 protease, amylase, lipase, cellulase, laccase, chitinase의 효소에 대해서 활성을 검정하였다. 대부분의 균주가 laccase 활성을 보였으며, protease, amylase 순으로 높게 나타났다. 담수 환경에서의 효소 활성 정보는 이들의 생태적 역할을 이해하고 산업적으로 활용하는데 기여할 수 있을 것이다.

• The Plant Pathology Journal
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• 제22권4호
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• pp.323-328
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• 2006

Serratia marcescens W1, isolated from cucumber-cultivated soil in Suwon, Korea, evidenced profound antifungal activity and produced the extracellular hydrolytic enzymes, chitinase and protease. In order to isolate the antifungal genes from S. marcescens W1, a cosmid genomic library was constructed and expressed in Escherichia coli. Transformants exhibiting chitinase and protease expression were selected, as well as those transformants evidencing antifungal effects against the rice blast fungus, Magnaporthe grisea, and the cucumber leaf spot fungus, Cercospora citrullina. Cosmid clones expressing chitinase or protease exerted no inhibitory effects against the growth of fungal pathogens. However, two cosmid clones evidencing profound antifungal activities were selected for further characterization. An 8.2 kb HindIII fragment from these clones conditioned the expression of antagonistic activity, and harbored seven predicted complete open reading frames(ORFs) and two incomplete ORFs. The deduced amino acid sequences indicated that six ORFs were highly homologous with genes from S. marcescens generating pyrroloquinoline quinone(PQQ). Only subclones harboring the full set of pqq genes were shown to solubilize insoluble phosphate and inhibit fungal pathogen growth. The results of this study indicate that the functional expression of the pqq genes of S. marcescens W1 in E. coli may be involved in antifungal activity, via as-yet unknown mechanisms.

• The Plant Pathology Journal
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• 제28권4호
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• pp.439-445
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• 2012

The chitinase producing Lysobacter enzymogenes C-3 has previously been shown to suppress plant pathogens in vitro and in the field, but little is known of the regulation of chitinase production, or its role in antimicrobial activity and biocontrol. In this study, we isolated and characterized chitinase-defective mutants by screening the transposon mutants of L. enzymogenes C-3. These mutations disrupted genes involved in diverse functions: glucose-galactose transpoter (gluP), disulfide bond formation protein B (dsbB), Clp protease (clp), and polyamine synthase (speD). The chitinase production of the SpeD mutant was restored by the addition of exogenous spermidine or spermine to the bacterial cultures. The speD and clp mutants lost in vitro antifungal activities against plant fungal pathogens. However, the gluP and dsbB mutants showed similar antifungal activities to that of the wild-type. The growth of the mutants in nutrient rich conditions containing chitin was similar with that of the wild-type. However, growth of the speD and gluP mutants was defective in chitin minimal medium, but was observed no growth retardation in the clp and dsbB mutant on chitin minimal medium. In this study, we identified the four genes might be involved and play different role in the production of extracellular chitinase and antifungal activity in L. enzymogenes C-3.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.117-126
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• 2010

A chitinase (CHT) and a protease (PRO) were purified from the culture supernatant of Serratia sp. TKU017, with shrimp shell as the sole carbon/nitrogen source. The molecular masses of CHT and PRO determined by SDS-PAGE were approximately 65 kDa and 53 kDa, respectively. CHT was inhibited by $Mn^{2+}$ and $Cu^{2+}$, and PRO was inhibited by most tested divalent metals and EDTA. The optimum pH, optimum temperature, pH stability, and thermal stability of CHT and PRO were pH 5, $50^{\circ}C$, pH 5-7, and <$50^{\circ}C$, and pH 9, $40^{\circ}C$, pH 5-11, and <$40^{\circ}C$, respectively. PRO retained 95% of its protease activity in the presence of 0.5 mM SDS. The result demonstrates that PRO is an SDS-resistant protease and probably has a rigid structure. The $4^{th}$-day supernatant showed the strongest antioxidant activity (70%, DPPH scavenging ability) and the highest total phenolic content ($196{\pm}6.2\;{\mu}g$ of gallic acid equiv./ml). Significant associations between the antioxidant potency and the total phenolic content, as well as between the antioxidant potency and free amino groups, were found for the supernatant. With this method, we have shown that shrimp shell wastes can be utilized and it is effective in the production of enzymes and antioxidants, facilitating its potential use in industrial applications and functional foods.

• 한국응용곤충학회지
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• 제32권3호
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• pp.330-337
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• 1993

벼멸구에 강한 병원성이 있는 Serratia marcescens, biotype A2a를 분리, 동정하였다. 벼 유묘에 분무한 후 성충-계절풍을 따라 비래하는 형태-을 공시하고 병원성을 조사하여 3~5일 만에 강한 살충력을 발견하였다. 따라서, 본 세균의 곤충병원성 관련 형질 탐색을 하기 위하여 Tn5로써 돌연변이를 시도한 후, Chitinase, Protease, DNase indicator media에서 돌연변이 계통을 분리하였다. 이들을 공시충에 병원성을 검정한 결과 Pro-Strain중에서 병원력이 현저히 떨어지는 현상을 관찰하였다. 공시충을 전자현미경(SEM, TEM)으로 관찰하여, abdomen의 전장부위와 표피사이에 다수의 세균이 증식하였음을 발견하였다. 곤충복부표피조직 중 cuticle층은 intact한 상태였다. 따라서, 이에 관련된 유전자를 분리하기 위해 genomic library 실험을 진행하고 있다.