• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.647-652
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• 2004

Thermophilic microorganisms capable of producing chitinase enzymes were screened from samples collected from several crater and geothermal areas. The chitinolytic microorganisms were grown in a selective medium containing colloidal chitin. The Bacillus K29-14 isolate was found to exhibit the highest chitinase and chitin deacetylase activities. When grown in a chitin-containing medium, the isolate produced extracellular chitinase after 24 h of incubation. The optimum temperature and pH for the chitinase were $55^\circ{C}$ and pH 7, respectively, while those for the chitin deacetylase were $55^\circ{C}$ and pH 8, respectively. The thermostable chitinase and chitin deacetylase also retained 80- 90% of their activity after incubation for 5 h at $70^\circ{C}$. The divalent cations $CoCl_2\;and\;NiCl_2$, increased the chitinase activity, while $ZnCl_2$, inhibited the enzyme. The chitin deacetylase was also activated by the presence of $MgCl_2$ and inhibited by $MnCl_2,\;NiCl_2,\;and\;CaCl_2$. A zymogram analysis revealed several forms of chitinase, with a 67 kDa form being the major enzyme.

• 방사선산업학회지
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• 제4권1호
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• pp.65-71
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• 2010

Two chitinase producing strains CHI2 and CHI4 were isolated from soybean rhizosphere soil. Both the strains belonged to Lysobacter enzymogenes as indicated by 16S rDNA sequence analysis. Though strain CHI2 and CHI4 produced extracellular chitinase, they differ in their chitinolytic activity. CHI4 produced approximately three times the higher amounts of enzyme than that of CHI2 under specified conditions. CHI2 produced $535.67U\;l^{-1}$ of chitinase after 48 h incubation with a specific activity of $3.91U\;mg^{-1}$ of protein while strain CHI4 produced $1584.13U\;l^{-1}$ of chitinase with a specific activity of $10.88U\;mg^{-1}$ protein. SDS-PAGE analysis indicated that the molecular weight of chitinase enzyme was approximately 45 kDa. A faint band with a molecular weight of 55 kDa reveals the possibility for the presence of another kind of chitin binding protein. Mutant library was developed by exposing the isolates to gamma rays at their $LD_{99}$ value (0.23 kGy). Totally, 11 mutants of CHI2 and CHI4 are reported to have enhanced chitinase activity. Several leaky mutant clones with decreased enzyme activity and a defective mutant (CHI2-M16) with complete loss of chitinase activity were also identified. CHI4-M18, CHI4-M8 and CHI4-M29 showed 78.8, 41.5, and 31.9% increased chitinase activity over wild type CHI4.

• 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 Applied Biological Chemistry
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• 제42권1호
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• pp.7-11
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• 1999

An extracellular chitinase of the selected strong antifungal microorganism, Serratia sp. 3095, was purified by salting out, affinity adsorption, Sepadex G-100 gel fitration, Sepadex G-75 gel fitration and DEAE Sepadex A-50 chromatography. The molecular weight of the purified chitinase was estimated to be 62,000 dalton by SDS-PAGE. Optimal pH and temperature of the chitinase were pH 7.5 and 45, respectively. The enzyme retained more than 80% of the activity between pH 5.5 and pH 10.5, and below $50^{\circ}C$ but was unstable above $60^{\circ}C$, below pH 5.0. The activity of the chitinase was inhibited about 60% by $Sn^{2+}$, 40% by $Hg^{2+}$ and $Ag^+$, 70% by AHA, 40% by iodoacetate, 35% by thiourea and p-CMB, but stabilized by SDS. $K_m$ value of the purified chitinase was 3.68 mg/ml for colloidal chitin. The chitinase from Serratia sp. 3095 showed antifungal activity to Fusariurm solani.

• 미생물학회지
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• 제38권1호
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• pp.50-53
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• 2002

백강균(Beauveria bassiana DGUM 34001)은 $24^{\circ}C$의 온도와pH 7.0의 초기 pH에서 최적의 균사체 생육을나타내었다. 사용한 복합배지 중 mushroom complex배지(MCM)에서 가장 우수한 균사생육을 나타내었다. Czapek-Dox 한천배지를 최소배지로 각각 탄소원, 질소원 및 인산원의 영향을 조사한 결과, glucose, soytone 및 sodium phosphate ($NaH_2$$PO_4$)에서 가장 우수한 균사 생육을 보여주었다. MCM액체배지에서 균사 배양 후 세포외 효소 활성을 측정한 결과,$\alpha$-amylase, lipase, chitinase, CMCase및 pretense의 비효소활성은 각각 297.0, 0.058, 0.33, 0.21 및 22.8 units/mg protein이었다. Casein과 soluble chitosan을 첨가할 경우 세포외 분비 pretense와 chitinase의 효소 활성 이 증가되었다.

• Applied Biological Chemistry
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• 제42권3호
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• pp.181-187
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• 1999

경주지역의 토양으로부터 Fusarium 속 식물병원균에 길항력을 갖는 chitinase 생산성 길항미생물을 분리할 수 있었으며, 이를 분류학적으로 동정하여 본 결과 Serratia proteamaculans 3095로 동정할 수 있었다. 이 균주가 생성하는 chitinase의 생성조건을 조사한 결과 탄소원으로 colloidal chitin이 가장 좋았으며 그 최적 농도는 0.15%이었고, glucose에 의해 chitinase 생산 유도를 억제받는 효소임을 알 수 있었다. 질소원에 의한 영향은 $(NH_4)_2SO_4,\;(NH_4)Cl$, peptone 등에 의해 chitinase 생산성이 증가되었고, $(NH_4)_2SO_4$와 peptone을 각각 0.1%씩 첨가하였을 때 chitinase 생산이 가장 좋았다. 또한 시드름병균 Fusarium oxysporum을 대상으로 in vitro, in vivo pot 실험을 통해 Serratia sp. 3095의 강한 방제력을 검증할 수 있었다.

• 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.

• Journal of Microbiology and Biotechnology
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• 제9권6호
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• pp.839-846
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• 1999

An extracellular chitinase-producing bacterial strain induced by colloidal chitin was isolated from sea sand and was identified to be a member of the genus Cytophaga. The chitinase was purified successively by 30-60% ammonium sulfate fractionation, and DEAE-Bio gel A column, Octyl-Sepharose CL-4B column, and DEAE-Bio gel A column chromatographies. The enzyme had a molecular mass of 59.75 kDa, and the amino terminal amino acid sequence was ATPNAPVISW MPTDXXLQNXS. The enzyme acted better on colloidal chitin as a substrate than on chitosan. For colloidal chitin and chitosan (Degree of Acetylation, 15-25%), $K_{cat}$ values were 0.60U/mg and 0.08U/mg, respectively. HPLC analysis of the enzymatic reaction products showed that the chitinase produced mostly N-acetyl-D-glucosarnine and di-N-acetylchitobiose. The optimum temperature and pH for the enzyme were $50^{\circ}C$ and 4.0, respectively. N-Bromosuccinimide and $Hg^{2+}$ inhibited the chitinase activity as much as 90%, and $Sb^{3+}$, diethylpyrocarbonate, and $Ag^{+}$ inhibited it by 50-70%.

• 미생물학회지
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• 제38권4호
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• pp.224-224
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• 2002

Chitin-degrading marine bacterial strain 98CJ11027 was isolated from bryozoa from the coastal area of Cheju Island, Korea, and identified as a member of the genus Vibrio. The molecular mass of the main extracellular chitinase (chitinase I), purified from strain 98CJ11027, was estimated to be 98 kDa. The optimal condition for chitinase I activity is pH 6.0 and 45℃. The activity was inhibited by $Fe^+2$ and$Cu^+2$. Chitinase I displayed the hydrolysis type of chitobiosidase and catalyzed reversed hydrolysis leading to the synthesis of tetraacetylchitotetraose.

• Journal of Microbiology
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• 제33권4호
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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.