• Journal of Microbiology and Biotechnology
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• 제24권12호
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• pp.1673-1678
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• 2014

The interactive inhibitory effects of pH and chloride on the catalysis of laccase from Trametes versicolor were investigated by studying the alteration of inhibition characteristics of sodium chloride at different pHs for the oxidation of 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid). At pH 3.0, the addition of sodium chloride (50 mM) brought about a 40-fold increase in $K{_m}^{app}$ and a 4-fold decrease in $V_{max}{^{app}}$. As the pH increased to 7.0, the inhibitory effects of sodium chloride became significantly weakened. The mixed-inhibition mechanism was successfully used to quantitatively estimate the competitive and uncompetitive inhibition strengths by chloride at two different pHs (pH 3.0 and 6.0). At pH 3.0, the competitive inhibition constant, $K_i$, was 0.35 mM, whereas the uncompetitive inhibition constant, $K{_i}^{\prime}$, was 18.1 mM, indicating that the major cause of the laccase inhibition by chloride is due to the competitive inhibition step. At a higher pH of 6.0, where the inhibition of the laccase by hydroxide ions takes effect, the inhibition of the laccase by chloride diminished to a great extent, showing increased values of both the competitive inhibition constant ($K_i=23.7mM$) and uncompetitive inhibition constant ($K{_i}^{\prime}=324mM$). These kinetic results evidenced that the hydroxide anion and chloride share a common mechanism to inhibit the laccase activity.

• 한국미생물·생명공학회지
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• 제45권4호
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• pp.330-342
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• 2017

Statistical design of experiments was employed to optimize the media composition for the production of laccase from Bacillus sp. PK4. In order to find the key ingredients for the best yield of enzyme production from the selected eleven variables viz yeast extract, glucose, zinc sulphate, copper sulphate, potassium chloride, magnesium sulphate, calcium chloride, ferrous sulphate, sodium chloride, potassium dihydrogen phosphate ($KH_2PO_4$) and dipotassium hydrogen phosphate ($K_2HPO_4$), Plackett-Burman design was applied. The $MgSO_4$, $FeSO_4$, and $CuSO_4$ showed positive estimate, and their concentration optimized further. The steepest ascent method and Box-Behnken method revealed that 1.5 mM $MgSO_4$, 0.33 g/l $FeSO_4$ and 1.41 mM $CuSO_4$ were optimal for the laccase production by Bacillus sp. PK4. This optimization strategy leads to enhancement of laccase production from 2.13 U/ml to 40.79 U/ml. Agro-wastes residues replace the carbon source glucose in the optimized media namely sugarcane bagasse, wheat bran, rice husk, and groundnut shell, among these groundnut shells (117 U/ml) was found to enhance the laccase production significantly. The laccase produced by Bacillus sp. PK4 was found to have the potential to degrade persistent organic pollutant benzo[a]pyrene.

• 미생물학회지
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• 제44권1호
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• pp.10-13
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• 2008

내분비장애 물질은 분해가 어렵고, 생물체에 축적되기 때문에 먹이그물을 통하여 결국 인간에게 피해를 준다. 리그닌 분해효소 군을 가진 백색부후균들은 다양한 난분해성 물질의 분해능이 우수하며, 국내에서 분리한 아교버섯은 내분비장애 물질에 속하는 프탈레이트의 분해능이 우수하다. 내분비장애 물질분해와 관련된 laccase cDNA를 발현벡터로 재조합하고 이를 형질전환 방법에 의하여 아교버섯으로 도입하였으며 도입된 발현벡터는 형질전환체의 염색체에 안정하게 존재하였다. 형질전환체들 중 가장 효소활성이 좋은 균주를 대상으로 분석한 결과 laccase 활성이 증가되었을 뿐만 아니라 내분비장애 물질의 분해능도 향상되었고, 동시에 다양한 내분비장애물질에 의한 에스트로겐 활성도 야생형 균주에 비하여 빠르게 감소시켰다.

• 한국균학회지
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• 제22권3호
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• pp.254-259
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• 1994

P. chrysosporium BKM-F-1767 및 C. subvermispora FP90031-SP. 균사를 이용하여 ligninase와 laccase 활성제고를 위한 배앙방법을 검토한 결과는 다음과 같다. P. chrysosporium의 왕복진탕배양시 (150 rpm) 배양액량은 45-60 ml가 ligninase 활성제고에 적합하였으며 60 ml 배양은 최대활성 출현일이 빨리 나타났다. C. subvermispora의 정치배양시, 2% M.E.+0.1% Y.E.+0.1% T.W.20+1mMVA 처리에서 ligninase 활성이 가장 높았고 laccase의 활성은 2% M.E.+0.1% Y.E.+0.1% T.W.20+6 mMBA에서 최고 수준을 나타내었다.

• 미생물학회지
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• 제33권4호
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• pp.252-256
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• 1997

담자균류 백색부후균의 일종인 흰구름버섯(Coriolus hirsutus)을 실험균주로 하여 수종의 난분해성 방향족염료의 분해능을 측정하였다. 사용된 4종류의 염료 중, triphenyl methane 염료인 bromophenol blue가 탈색율 95% 이상으로 가장 잘 탈색되었으며, Congo red와 Poly R-478은 이보다는 낮은 57%, 55%가 탈색되었다. 그러나, heterocyclic 염료인 methylene blue는 본 균주에 의해 거의 탈색되지 않았으며, UV-visible spectrum상에서의 심색성 이동만 관찰되었다. 세포외 laccase와 peroxidase의 활성은 각 염료의 탈색율과 비례하여 나타났으며, 최대 활성 또한 최대 탈색시기에 관찰되었다. 효소의 활성 염색시 모든 염료의 탈색배지에서 공통적인 laccase와 peroxidase의 활성 띠가 관찰되었다. 이러한 결과로 볼 때, 세포외 laccase와 peroxidase가 난분해성 염료의 탈색에 중요한 역할을 할 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제28권12호
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• pp.2057-2063
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• 2018

Laccases can oxidize a variety of phenolic and non-phenolic substrates including synthetic dyes. In this research, a laccase gene Lcc9 from Laccaria bicolor was chemically synthesized and optimized to heterogeneous expression in Pichia pastoris and Arabidopsis thaliana. The properties of recombinant laccase expressed by P. pastoris were investigated. The laccase activity was optimal at 3.6 pH and $40^{\circ}C$. It exhibited $K_m$ and $V_{max}$ values of $0.565mmol\;l^{-1}$ and $1.51{\mu}mol\;l^{-1}\;min^{-1}$ for ABTS respectively. As compared with untransformed control plants, the laccase activity in crude extracts of transgenic lines exhibited a 5.4 to 12.4-fold increase. Both laccases expressed in transgenic P. pastoris or A. thaliana could decolorize crystal violet. These results indicated that L. bicolor laccase gene may be transgenically exploited in fungi or plants for dye decolorization.

• 한국버섯학회지
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• 제20권1호
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• pp.29-33
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• 2022

본 연구에서는 톱밥재배용 표고(Lentinula edodes) 품종에 대한 목질계 섬유소의 분해특성을 분석하였다. 국산 표고 품종 참아람, 산백향, 산조 713호, 산조 715호, 산조 718호를 대상으로 RBBR (Remazol Brilliant Blue R) 탈색능, 목질계 섬유소 분해 효소인 MnP와 laccase의 활성을 비교 분석하였다. 5개 품종의 탈색능과 효소활성은 품종별로 다른 양상을 보였다. 리그닌의 첨가에 따른 RBBR 탈색능을 조사한 결과, 참아람과 산조 713호가 각각 배양 3일과 5일째부터 우수한 분해능을 보였다. 섬유소 분해 효소인 MnP와 laccase의 활성은 산조 713호가 배양 2일째 MnP 활성이 1,213 U/mg, laccase 활성이 1,421 U/mg, 다음으로 참아람이 배양 7일째 MnP 활성이 1,921 U/mg, laccase 활성이 2,123 U/mg으로 최고 활성을 나타냈다. 이러한 결과는 표고 육종에 있어 리그닌 분해능이 우수한 균주의 선발이 가능함에 따라 교배균주의 육종 모본 활용에 효율적일 것으로 판단된다.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 1998년도 제1회 총회 및 추계학술발표회
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• pp.30-30
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• 1998

• Journal of Microbiology and Biotechnology
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• 제29권12호
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• pp.1861-1872
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• 2019

In the present work, we isolated and identified Aspergillus sydowii NYKA 510 as the most potent laccase producer. Its medium constituents were optimized to produce the highest possible amount of laccase, which was after 7 days at 31℃ and pH 5.2. Banana peel and peptone excelled in inducing laccase production at concentrations of 15.1 and 2.60 g/l, respectively. Addition of copper sulfate elevated enzyme yield to 145%. The fungus was employed in a microbial fuel cell (MFC). The best performance was obtained at 2000 Ω achieving 0.76 V, 380 mAm^-2, 160 mWm^-2, and 0.4 W. A project to design a self-sufficient lighting unit was implemented by employing a system of 2 sets of 4 MFCs each, connected in series, for electricity generation. A scanning electron microscopy image of A. sydowii NYKA 510 was utilized in algorithmic form generation equations for the design. The mixed patterning and patterned customized mass approach were developed by the authors and chosen for application in the design.

• Mycobiology
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• 제42권2호
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• pp.193-197
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• 2014

Laccase activity of Pleurotus ostreatus is significantly increased by the addition of apple pomace. Among various conditions, the best concentration of apple pomace and cultivation time for the production of laccase by P. ostreatus was 2.5% and 9 days, respectively. Reverse transcription polymerase chain reaction analyses of laccase isoenzyme genes, including pox1, pox3, pox4, poxc, poxa3, and poxa1b, revealed a clear effect of apple pomace on transcription induction. Our findings reveal that the use of apple pomace can be a model for the valuable addition of similar wastes and for the development of a solid-state fermenter and commercial production of oyster mushroom P. ostreatus.