• Mycobiology
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• 제35권2호
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• pp.91-96
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• 2007

In the present study we first report in Korea the identification and characterization of Fusarium oxysporum isolated from rotten stems and roots of paprika (Capsicum annuum var. grossum) at Masan, Kyungsangnamdo in 2006. The fungal species produced white aerial mycelia accompanying with dark violet pigment on PDA. The optimal temperature and pH for the growth of the species was $25^{\circ}C$ and pH 7, respectively. Microscopic observation of one of isolates of the species shows that its conidiophores are unbranched and monophialides, its microconidia have oval-ellipsoidal shape with no septate and are of $3.0{\sim}11{\times}1.5{\sim}3.5\;{\mu}m$ sizes, its macroconidia are of $15{\sim}20{\times}2.0{\sim}3.5\;{\mu}m$ sizes and have slightly curved or slender shape with $2{\sim}3$ septate. The results of molecular analysis show that the ITS rDNA of F. oxysporum from paprika shares 100% sequence identity with that of known F. oxysporum isolates. The identified species proved it's pathogenicity by causing rotting symptom when it was inoculated on paprika fruits. The growth of F. oxysporum from paprika was suppressed on PDA by agrochemicals such as benomyl, tebuconazole and azoxystrobin. The identified species has the ability of producing extracelluar enzymes that degrade cellobiose and pectin.

• Journal of Microbiology
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• 제45권6호
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• pp.485-491
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• 2007

The effects of biological pretreatment on the Japanese red pine Pinus densiflora, was evaluated after exposure to three white rot fungi Ceriporia lacerata, Stereum hirsutum, and Polyporus brumalis. Change in chemical composition, structural modification, and their susceptibility to enzymatic saccharification in the degraded wood were analyzed. Of the three white rot fungi tested, S. hirsutum selectively degraded the lignin of this sortwood rather than the holocellulose component. After eight weeks of pretreatment with S. hirsutum, total weight loss was 10.7%, while lignin loss was the highest at 14.52% among the tested samples. However, holocellulose loss was lower at 7.81 % compared to those of C. lacerata and P. brumalis. Extracelluar enzymes from S. hirsutum showed higher activity of ligninase and lower activity of cellulase than those from other white rot fungi. Thus, total weight loss and changes in chemical composition of the Japanese red pine was well correlated with the enzyme activities related with lignin- and cellulose degradation in these fungi. Based on the data obtained from analysis of physical characterization of degraded wood by X-ray Diffractometry (XRD) and pore size distribution, S. hirsutum was considered as an effective potential fungus for biological pretreatment. In particular, the increase of available pore size of over 120 nm in pretreated wood powder with S. hirsutum made enzymes accessible for further enzymatic saccharification. When Japanese red pine chips treated with S. hirsutum were enzymatically saccharified using commercial enzymes (Cellulclast 1.5 L and Novozyme 188), sugar yield was greatly increased (21.01 %) compared to non-pre treated control samples, indicating that white rot fungus S. hirsutum provides an effective process in increasing sugar yield from woody biomass.

• 대한화장품학회지
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• 제41권3호
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• pp.263-268
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• 2015

본 연구는 오디씨 에탄올 추출물(MSE)의 멜라닌 합성 저해 효과를 밝히는 것이다. 먼저 MSE의 melan-a 세포를 이용한 멜라닌 합성 저해 실험결과, 독성을 보이지 않는 $10{\mu}g/mL$의 농도까지 멜라닌 합성 저해 효과를 나타내었다. 또한 tyrosinase, tyrosinase-related protein-1 (TRP-1) 단백질의 발현이 저해되었으며, extracelluar signal-regulated protein kinase (ERK)의 발현을 농도 의존적으로 증가시키는 MSE의 기전을 확인하였다. 뿐만 아니라, 제브라피쉬를 이용한 in vivo 모델의 실험에서도 색소 발생이 저해됨을 관찰하였다. 따라서 오디씨로 부터 획득한 에탄올 추출물이 ERK 단백질의 발현으로 인해 멜라닌 생합성을 억제할 수 있음을 밝혔다.

• 한국토양동물학회지
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• 제4권2호
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• pp.101-106
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• 1999

지렁이 꼬리재생 초기에 발현되는 피브리노겐 분해효소의 활성은 세포외기질의 재구성에 연관되어 있을 것으로 생각된다. 본 연구에서는 지렁이의 꼬리 재생 중에 발현된 피브리노겐 분해효소의 활성과 특성을 밝히고자 하였다. 지렁이의 꼬리 재생 중에 발현되는 피브리노겐 분해효소는 최소 7개이며 그 분자량은 각각 58, 45, 32, 27, 23, 19 그리고 12kDa로 측정되었다. 피브리노겐 분해효소의 활성은 절단 후 1일부터 효소의 활성이 나타나서 7일까지 거의 유사한 정도의 활성이 유지되었으며, 7일 이후부터는 이 효소들의 활성이 급격히 감소하여 14일에는 그 활성이 대조군 수준으로 회복되었다. 지렁이 꼬리 재생 중 발현된 모든 피브리노겐 분해효소는 PMSF와 aprotinin를 처리하였을 때 효소들의 활성이 억제되었다. 또한 Ca$^{2+}$의 제거는 이효소의 활성에 영향을 미치지 않는 것으로 나타났다. 이러한 결과를 통하여 지렁이 꼬리재생시 발현되는 피브리노겐 분해효소는 serine계 단백질 분해효소임을 알 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제11권2호
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• pp.222-228
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• 2001

Vibrio metschnikovii strain RH530 is a non-pathogenic, industrially-important alkaline protease producer which has been isolated from wastewater. In this paper, we report on the transformation of this strain by using the method of electroporation. A field strength of $7.5\;kVcm^{-1}$ and $25\;{\mu}F$, and using a 0.2-cm cuvette, appeared to be the optimal conditions for electroporation of the cells with the recombinant pSBCm plasmid carrying the vapK alkaline protease gene and the ColE1 replicon. Cells were subjected to osmotic shock in order to remove extracelluar DNase, and adding 200 mM of sucrose to electroporation buffer cells showed an increased transformation efficiency. Maximum efficiency of transformation was obtained at an early exponential growth phase. Using all of the conditions mentioned above, we routinely obtained a transformation efficiency of more than $10^4{({\mu}g\;plasmid\;DNA)}^{-1}$. The stability of the plasmid pSBCm in V. metschnikovii RH530 was 25% after 18h of growth (27 generations) in the medium without antibiotic selection. The insertion of the par locus to the pSBCm increased the stability of the plasmid up to 42% without selective pressure. The increase in plasmid stability was accompanied by the increase in the productivity of alkaline protease in the recombinant V. metschnikovii strain RH530. Determining optimal conditions for the transformation of the industrially-important, nonpathogenic Vibrio strain, and the improvement of plasmid stability by introducing the par locus into the high copy number plasmid vector, will allow the development of procedures involved in the genetic manipulation of this strain, particularly for its use in the production of industrial enzymes such as alkaline protease.

• 환경생물
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• 제20권1호
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• pp.85-90
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• 2002

인위적으로 pH 구배가 조성된 회분배양 시스템 (batch culture system)내에서 산성화에 따른 종속영양 세균 군집의 종조성 변화를 분석하였다. 총세균의 개체수는 산성화에 영향을 받지 않았으며, 종속영양세균 군집의 크기는 pH가 낮아질수록 감소하였다. 전 pH구간에서 분리된 종속영양 세균들은 모두 12속 22종으로 나타났으며, 이중 그람음성 세균은 64%,그람양성 세균은 36%의 비율로 분포하였다. pH가 낮아짐에 따라 그람양성 세균의 분포 비율은 감소하는 반면, 그람음성 세균의 분포 비율은 증가하는 양상을 보였다. 각 pH 구간별 속의 분포 비율은 pH 7에서는 12개 속이 출현하였으나, pH 3에서는 5개 속만 출현하여 pH가 낮아짐에 따라 속의 다양성이 감소하는 양상을 나타내였다. 세포외 효소의 활성도는 $0.008-0.292\;\mu{M}\ell^{-1}\;hr^{-1}$의 범주로 나타났고, 산성화에 따라 세포외 효소의 활성도는 급격히 감소하여 pH 5이하에서는 5-38%의 낮은 활성을 나타내었다.