• Journal of the Korean Wood Science and Technology
• /
• 제25권2호
• /
• pp.1-20
• /
• 1997

목재를 분해시키는 담자균류들은 목재 및 목질복합체에 쉽사리 침투하여 복잡한 리그노셀룰로오스 복합체를 분해시킨다. 이러한 분해에는 많은 효소시스템들이 복합적으로 작용하면서 상호 협동하는 것으로 보고되고 있다. 지금까지 일려진 효소들은 통상 3개의 그룹으로 나눌 수 있는데 그 하나는 목재성분을 직접적으로 공격하는 효소균들, 예를 들면 cellulase complex, laccase(LAC), lignin peroxidase(LIP), horse-radish peroxidase(HRP), manganese-independent peroxidase(MIP) 및 protocatechuate 3,4-dioxygenase(PCD) 등이 있고, 두번째 그룹으로서 manganese-dependent peroxidase(MnP), aryl alcohol oxidase(AAO) 및 glyoxal oxidase(GLO) 등인데, 이들 효소들은 목질을 직접적으로 공격하지 않고 제1그룹의 효소들과 협동하여 작용하는 것으로 알려지고 있다. 제3그룹의 효소들은 glucose oxidase(GOD) 및 cellobiose : quinone oxidoreductase(CBQ)로서 feedback type의 효소들로서 목재고분자의 분해시 대사의 고리를 결합시켜 주는 매우 중요한 기능을 하는 효소군들이다. 그러나 이 이외에도 다른 분해기구가 밝혀지고 있으며 기타 효소들에 의한 리그노셀룰로오스의 분해반응기구의 해명에는 상당한 시간이 걸릴 것으로 사료된다.

• Journal of Microbiology and Biotechnology
• /
• 제21권9호
• /
• pp.995-1000
• /
• 2011

The bioremediation potential of crude oil by Polyporus sp. S133 pre-grown in wood meal was investigated in two separate experiment trials; liquid medium and soil. The effect of three nutrients (glucose, polypeptone, and wood meal), oxygen flow, and some absorbent on the efficiency of the process was also evaluated. Degradation of crude oil in soil was significantly increased with an addition of oxygen flow and some absorbent (kapok and pulp). The highest degradation rate of crude oil was 93% in the soil with an addition of 10% kapok. The present study clearly demonstrates that, if suitably developed, Polyporus sp. S133 could be used to remediate soil contaminated with crude oil.

• Journal of the Korean Wood Science and Technology
• /
• 제50권3호
• /
• pp.159-166
• /
• 2022

CO₂ emissions are the primary reason for global warming; hence, biological and chemical technologies for converting CO₂ into useful compounds are being actively studied. Biological methods using enzymes can convert CO₂ under mild conditions. Formate dehydrogenase (FDH) is a representative CO₂ conversion enzyme. Its function was revealed after isolation from bacteria, yeast, and plants. In this study, we evaluated the CO₂ conversion potential of FDH isolated from wood-rotting fungi. After isolating the FDH gene (TvFDH) from Trametes versicolor, we cloned the full-length FDH from T. versicolor and expressed it in a cell-free expression system. The gene encoding TvFDH was identified as 1,200 bp open reading frame (ORF) and the expected molecular weight of the protein was approximately 42 kDa. Overexpression of the recombinant crude protein including TvFDH was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Enzyme activities and metabolite analyses confirmed the efficiency of TvFDH for CO₂ reduction.

• 한국약용작물학회지
• /
• 제25권5호
• /
• pp.282-289
• /
• 2017

Background: To investigate the possibility of using Asarum sieboldii as an environment-friendly fumigant for protecting organic cultural heritages, the inhibitory effect of A. sieboldii extract against wood rot fungi on Hanji was examined. Methods and Results: The physical, optical, and morphological properties of Hanji inoculated with Trametes versicolor and Tyromyces palustris, and exposed to the n-hexane fraction of A. sieboldii extract, were measured. The physical properties were expressed as weight loss, zero-span tensile strength and viscosity and the optical properties were depicted by luminance and chromaticity ($L^*$, $a^*$, and $b^*$). The results showed that, the n-hexane fraction of A. sieboldii extract inhibited the growth of fungi on Hanji, and preserved its condition. At a concentration of 25 mg, the n-hexane fraction of A. sieboldii extract maintained zero-span tensile strength, increased viscosity, and restricted discoloration of Hanji. It also was confirmed that the weight of fungi infested Hanji exposed to the extract did not decrease. Scanning electron microscopic images revealed that the spores and hyphae of T. versicolor and T. palustris were not present on Hanji during treatment with > 25 mg of the n-hexane fraction of A. sieboldii extract. Conclusions: These results indicate that the n-hexane fraction of A. sieboldii extract by virtue of its antifungal effectiveness may help in preserving Korean paper cultural heritages, including Hanji.

• Journal of the Korean Wood Science and Technology
• /
• 제46권5호
• /
• pp.497-510
• /
• 2018

본 연구에서는 과열증기를 이용하여 열처리한 낙엽송재의 야외 내후성 시험을 통해 부후균과 해충에 대한 저항성을 평가하였다. 12개월간 진행된 야외 내후성 시험 결과, 무처리재는 흰개미에 의한 피해가 두드러지게 나타났지만 방부목재와 과열증기 열처리재에서는 육안으로 관찰되는 피해는 발견되지 않았다. 무처리재와 방부목재는 약 5%의 질량 감소를 보였으며, 과열증기 열처리재는 약 1%의 질량 감소를 보였다. 야외 내후성 시험이 진행된 후 방부목재에 남아있는 방부약제의 함량이 야외 내후성 시험 전보다 감소한 것으로 보아 야외 내후성 시험이 진행되는 동안 방부약제가 일부 용출된 것으로 보이며, 이에 따라 방부목재의 질량 감소가 무처리재와 유사한 수준으로 나타난 것으로 생각되었다. 과열증기를 이용한 열처리는 방부약제 주입과 같은 화학적인 처리 없이 친환경적으로 목재의 부후균과 해충에 대한 저항성을 개선시킬 수 있는 가능성이 확인되었으며, 이를 위하여 장기적인 관찰이 추가적으로 필요할 것이라 생각된다.

• Journal of the Korean Wood Science and Technology
• /
• 제47권1호
• /
• pp.21-32
• /
• 2019

In order to investigate the decay process of wood treated with preservative, waterproofing agent and their compound systems, a full-cell process was applied to impregnate the sapwood of poplar (Populus cathay) at paraffin wax emulsion concentrations of 0.5% and 2.0%, Copper Azole (CA) concentrations of 0.3% and 0.5%, and their four compound systems, respectively. Leaching tests and laboratory decay resistance against the white-rot fungus Corious versicolor (L.) Murrill for treated wood were carried out according to the America Standard E11-06 and China Standard GB/T 13942.1-2009. At certain time intervals during the decay test, samples were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction technique (XRD) to investigate the time-dependent changes of chemical components and crystalline structure, thus clarifying the decay mechanisms. The results suggested that white-rot fungi degrade hemicellulose and lignin in the wood cell wall first, followed by a simultaneous degradation of polysaccharides and lignin. Besides, CA could not only slower the decomposition of both hemicellulose and lignin, but also reduce the degradation amount of hemicellulose. However, paraffin wax emulsion at high concentration had a negative effect on the impregnation of CA for the compound system treated wood.

• Journal of the Korean Wood Science and Technology
• /
• 제40권6호
• /
• pp.424-430
• /
• 2012

본 연구에서는 국내에서 자생하는 백색부후균인 겨울우산버섯(Polyporus brumalis)을 소나무 시편에 배양하여 목재 처리에 의한 리그닌 분해효소의 활성변화를 조사하고 목재의 분해가 일어나는 동안 중량감소율 및 리그닌 감소율을 통해 분해능을 확인하고 여기에 관여하는 유전자의 발현을 조사하였다. SSC (Shallow Stationary Culture) 액체배지에 목재 시편을 넣고 겨울우산버섯을 배양하였을 때 무처리구에서는 laccase의 활성이 20일 이후 감소하는 반면, 시편 처리구에서는 활성이 계속 증가되었다. 특히, 60일 전후의 처리구에서 무처리구에 비해 10배 이상 높은 활성을 나타내었다. 또한, 겨울우산버섯에 의한 소나무칩의 중량 감소율과 리그닌 감소율은 80일 후 각각 23.4%와 6.3%로 나타났다. 40일 배양한 목질칩에서 분리한 겨울우산버섯의 pblac1의 유전자 발현은 무처리구에 비해 소나무 칩 처리구에서 약 3배 정도 높게 나타났다. 이상의 결과로 백색부후균에 의한 목재칩 처리에 의해 리그닌 분해효소의 활성이 증가되며 pblac1이 리그닌 분해에 중요한 역할을 하는 것으로 보여진다. 따라서 백색부후균의 리그닌분해효소 유전자 발현을 조절함으로써 리그닌 분해능이 우수한 균주 개발이 가능하고 목질에탄올 생산 전처리에 효율적으로 이용할 것으로 기대된다.

• Journal of Microbiology and Biotechnology
• /
• 제10권6호
• /
• pp.737-752
• /
• 2000

Wood-rotting basidiomycetous fungi are the most efficient degraders of lignin on earth. The white-rot fungus Phanerochaete chrysosporium has been used as a model microorganism in the study of enzymology and its application. Because of the ability of the white-rot fungus to degrade lignin, which has an irregular structure and large molecular mass, this fungus has also been studied in relation to degrading and mineralizing many environmental pollutants. The fungus includes an array of enzymes, such as lignin peroxidase (LiP), manganese-dependent peroxidase (MnP), cellobiose:quinone oxidoreductase, and $H_2O_2$-producing enzymes and also produces many other components of the ligninolytic system, such as veratryl alcohol (VA) and oxalate. In addition, the fungus has mechanisms for the reduction of degradation intermediates. The ligninolytic systems have been proved to provide reductive reactions as well as oxidative reactions, both of which are essential for the degradation of lignin and organopollutants. Further study on the white-rot fungus may provide many tools to both utilize lignin, the most abundant aromatic polymer, and bioremediate many recalcitrant organopollutants.

• Journal of the Korean Wood Science and Technology
• /
• 제38권6호
• /
• pp.579-586
• /
• 2010

목련과 식물의 활용도 제고를 위해 항산화제, 식품첨가제 개발에 필요한 항균 및 항산화 활성을 검정하였다. 우선 목련과 총 11종 식물의 수피, 잎, 목부, 꽃 및 열매의 에탄올 조추출물을 1,000 ${\mu}g/m{\ell}$로 조제하여 항진균 활성을 조사하였다. 그 결과 일본목련 수피가 백색부후균인 Trametes versicolor를 제외한 모든 공시균주에 대하여 50% 이상의 균사생장억제율을 나타내어 항균활성이 가장 높은 것으로 나타났다. 그 다음이 일본목련 목부로 탄저병균인 Glomerella cingulata와 목재부후균인 T. versicolor, Tyromyces palustris를 제외한 공시균주에 대하여 50% 이상의 균사생장억제율을 나타내었다. 수종별로는 일본목련이 가장 항균활성이 우수하여 수피, 잎, 목부 모두 항균활성이 있는 것으로 나타났으며 그 다음이 목련, 함박꽃나무 순이었다. 부위별로는 수피가 가장 활성이 우수하였으며 백목련, 자목련의 경우에는 다른 부위에 비해 꽃의 항균활성이 우수하였다. 또한, 프리라 디칼소거능을 측정하여 항산화활성을 검정한 결과에서는 100 ${\mu}g/m{\ell}$의 농도에서 태산목 수피와 잎이 70% 이상의 소거능을, 그리고 초령목 수피와 잎, 흑오미자 줄기 및 남오미자 줄기가 90% 이상의 소거능을 나타내었다. 특히, 흑오미자 줄기 및 남오미자 줄기는 10 ${\mu}g/m{\ell}$의 농도에서 각각 41.2%와 44.4%의 소거능을 나타내어 합성 항산화제인 butylated hydroxyanisole 및 천연항산화제인 ${\alpha}$-tocopherol과 동등한 항산화활성이 있는 것으로 밝혀졌다. 금후 흑오미자 및 남오미자 줄기와 같이 항산화활성 우수 시료는 활성물질 분리 및 구조 동정, 안전성 검정 등을 통하여 식품보존제 및 화장품 소재로 개발이 가능할 것으로 사료되었다.

• 임산에너지
• /
• 제17권1호
• /
• pp.56-70
• /
• 1998

This study was carried out to investigate the structural characteristics of kraft lignin and the wood degrading characteristics, the productivity of ligninolytic enzymes and the enzymatic degradation of kraft lignin by white-rot fungi. To purify kraft lignin, precipitation of kraft pulping black liquors of pitch pine meal was done by titration with lN $H_{2}SO_{4}$ reaching to pH 2, and isolation of the precipitates done by centrifugation. The isolated precipitates from pitch pine were redissloved in lN NaOH, reprecipitated by titration with lN $H_{2}SO_{4}$, washed with deionized water, and kept ofr analysis after freeze drying. Fractionation of the precipitates in solution by successive extraction with $CH_{2}Cl_{2}$ and MeOH, and the fractionates were named SwKL, SwKL I, SwKL II, and SwKL III for pitch pine kraft lignin. The more molecular weights of kraft lignin increased, the less phenolic hydroxyl groups and the more aliphatic hydroxyl groups. Because as the molecular weights increased, the ratio of etherified guaiayl/syringyl(G/S ratio) and the percentage were increased. The spectra obtained by 13C NMR and FTIR assigned by comparing the chemical shifts of various signals with shifts of signals from autherized ones reported. The optimal growth temperature and pH of white-rot fungi in medium were $28^{\circ}C$ and 4.5-5.0, respectively. Especially, in temperature and pH range, and mycelial growth, the best white-rot fungus selected was Phanerochaete chrysosporium for biodegradation. For the degradation pathways, the ligninolytic fungus jcultivated with stationary culture using medium of 1% kraft lignin as a substrate for 3 weeks at $28^{\circ}C$. The weight loss of pitch pine kraft lignin was 15.8%. The degraded products extracted successively methoanol, 90% dioxane and diethyl ether. The ether solubles were analyzed by HPLC. Kraft lignin degradation was initiated in $\beta$-O-4 bonds of lignin by the laccase from Phanerochaete chrysosporium and the degraded compounds were produced from the cleavage of $C\alpha$-$C\beta$ linkages at the side chains by oxidation process. After $C\alpha$-$C\beta$ cleavage, $C\alpha$-Carbon was oxidized and changed into aldehyde and acidic compounds such as syringic acid, syringic aldehyde and vanilline. And the other compound as quinonemethide, coumarin, was analyzed. The structural characteristics of kraft lignin were composed of guaiacyl group substituted functional OHs, methoxyl, and carbonyl at C-3, -4, and -5 and these groups were combinated with $\alpha$ aryl ether, $\beta$ aryl ether and biphenyl. Kraft lignin degradation pathways by Phanerochaete chrysosporium were initially accomplished cleavage of $C\alpha$-$C\beta$ linkages and $C\alpha$ oxidation at the propyl side chains and finally cleavage of aromatic ring and oxidation of OHs.