• The Korean Journal of Mycology
• /
• v.44 no.3
• /
• pp.193-195
• /
• 2016

Korean ginseng (Panax ginseng) possesses various biological and pharmacological properties. Damping-off is a critical disease on ginseng seedlings, which is caused by the fungal pathogens Rhizoctonia solani and Pythium sp.. This disease is generally controlled by the application of fungicides, but also biological control is an efficient and environmentally friendly way to prevent ginseng damping-off. In a previous study, we screened soil-borne bacteria with potential applications as biological control agents for ginseng damping-off and selected the bacterial strain Streptomyces sp. A3265, producing antifungal substances guanidylfungin and methylguanidylfungin. In this study, we investigated control efficacy of Streptomyces sp. A3265 against ginseng damping-off in the field. As a result, the incidence of damping-off was significantly reduced when soaking ginseng seeds in the culture broth of Streptomyces sp. A3265.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.19 no.3
• /
• pp.63-72
• /
• 2011

Benzalkonium chloride is most widely used in S. Korea as a disinfectant in livestock husbandry. Inhibition of biogas potentials were investigated with three different doses of benzalkonium chloride in swine slurry. The system was operated at batch mode. The inhibition rates were 10%, 30~40% and >70% at the dose of 10ppm, 40ppm and 80ppm, respectively assuming it was zero percent in case of no dose. Enzymatic activities were analyzed to determine the enzymatic type which was inhibited by benzalkonium chloride. The acid phosphatase, alkaline phosphatase and protease were shown negatively correlated with biogas potential. Correlation of ${\alpha}$-glucosidase and biogas potentials was observed not high (p<0.01, r=-0.426) while benzalkonium chloride (r=-0.853, p<0.01) and acid phosphatase (p<0.01) with biogas potentials were significantly and negatively correlated. The effect of benzalkonium chloride on Escherichia coli were also evaluated by disc diffusion method. As increase of benzalkonium concentration, inhibition zone of anaerobic bacteria was extended. It revealed that benzalkonium chloride significantly deteriorated biogas potential through inhibition of acetogenic bacteria.

• Korean Journal of Organic Agriculture
• /
• v.29 no.2
• /
• pp.257-273
• /
• 2021

Koreans consume cham-chwi (Aster scaber thunb.) as a common vegetable in a meal because of its bitter taste and rich flavor. In addition, it is the crop with the most residual pesticides detected in the last five years. Among the detected pesticides, the most common was azoxystrobin, which is a drug used primarily to prevent the leaf spot disease of A. scaber caused by Septoria sp.. We isolated the microorganisms that antifungal activity against Septoria sp.. The optimum incubation conditions (temperature, pH and growth medium) were examined for the growth of the isolates. Additionally, cellulase and protease activity and siderophore production ability were also examined. According to 16S rRNA sequencing of the isolate was affiliated to Paenibacillus polymyxa JE201. Largest inhibition zone measuring up to 9.2 mm was observed for P. polymyxa JE201 after 7 days of inoculation. P. polymyxa JE201 strain showed antifungal activity against various fungal phytopathogens Altanaria sp., Botrytis cinerea, Colletotrichum acutatum, Fusarium oxysporum, Phytophthora capsici, Ph. drechesleria, Rhizoctonia solani and Stemphylium sp.. Based on these observations, P. polymyxa. JE201 can be used as a promising biocontrol agent for preventing the leaf spot disease and other phytopathogens.

• Korean Journal of Environmental Biology
• /
• v.40 no.4
• /
• pp.398-404
• /
• 2022

Bis(2-ethylhexyl) phthalate (DEHP) is one of the plasticizers used in the polyvinyl chloride(PVC) industry. It is known to be easily released into the environment. In this study, we investigated effects of DEHP on growth, metabolic pathway, and virulence gene expression in soil-borne bacterial plant pathogen, Pectobacterium carotovorum SCC1 using in vitro assays. As a result, DEHP at 20 ㎍ mL^-1 did not affect the growth, cell membrane permeability, or ATPase activity of P. carotovorum SCC1. However, it decreased succinyl-CoA synthase (SCS) activity in the tricarboxylic acid (TCA) cycle. Relative expression levels of virulence genes encoding pectate lyase and pectin were differentially influenced by DEHP treatment. These results suggest that biological characteristics of P. carotovorum might be influenced by DEHP in soil.

• Applied Biological Chemistry
• /
• v.43 no.2
• /
• pp.86-94
• /
• 2000

In order to develop the enzymatic hydrolysis system concerned with taste and flavor, strains having the high hydrolyzing activity on the soy protein were selected from some traditional Mejus. Two molds and one bacterium producing enzymes which were different in character of hydrolysis were isolated and identified. Leucine and azodye enzyme activities of both M4 and M5 were relatively high among in the isolated molds. And, leucine enzyme activity of B16 was the lowest in the isolated bacteria. These strains were isolated as microorganisms having a dissimilar hydrolysis pattern on the soy protein by enzymatic reactions. Mold M4 on the culture solid media was mycelium colors of white and its sclerotia colors were changed from white to black. According to the result of slide culture, radial conidial head, subclavate vesicle, conidia of subglobose, stipes of uncolored with smooth walls and metula and phialides were existed. Because M4 was taxonomically similar to the characteristics of Aspergillus oryzae (ahlburg) species, M4 was identified and named as Aspergillus oryzae M4.Mold M5 showed white and black mycelium on the MEA medium. Mold M5 colony exhibited grayish-green color and have long(7 mm) sporangiophores at slide culture. Sporangia became brownish-gray and the wall of larger sporangia was broken to form small collars, and smaller sporangia were fomed continually from large basal membrane. Columella is globose and hyaline, and sporangiospores are ellipsoidal of small diameter$(80\;{\mu}m)$. Because M5 was taxonomically similar to the Mucor circinelloides of zygomycetes, M5 was was identified and named as Mucor circinelloides M5. Bacteria B16 colony was opaque white, circular and lobate, and had rod shaped endospore. B16 was found positive in stain, catalase, ${\beta}-glucosidse$ and V-P tests. B16 was found to utilize D-fructose, ${\alpha}-D-glucose$, maltose, D-mannose, D-raffinose, stachyose and sucrose. By the morphological and physiological results, the characteristics of B16 was thought to correspond to that of Bacillus megaterium. However, fatty acid composition was similar to Paenibacillus marcerans, requiring further study for the definite identification. Accordingly, Bacteria B16 was provisionally classified and named as Bacillus megaterium B16.

• Microbiology and Biotechnology Letters
• /
• v.6 no.4
• /
• pp.187-196
• /
• 1978

Antimetabolite N-2292 substance, an antagonist of L-aspartic acid and L-glutamic acid was isolated from the fermentation broth of Streptomyces. Taxonomical study on the producing strain made it a related species of Streptomyces albulus judged by cultural characteristics and carbon utilization. N-2292 substance was isolated as amorphous white powder with melting point at 185$^{\circ}C$. From the physicochemical characteristics of the substance, it was peptide like substance. It was active against Gram positive and Gram negative bacteria but negative against yeast and mold in its biological properties. It was reversed by L-Asp and L-Glu on the synthetic medium.

• The Korean Journal of Mycology
• /
• v.36 no.1
• /
• pp.93-97
• /
• 2008

A $Ca^{2+}-independent$ microbial transglutaminase (mTGase) from the actinomycete Streptomyces mobaraensis IFO13819 is a useful enzyme in the food industry. It is consists 406 amino acid residues, which comprised leader and pro region of 75 amino acid residues and the structure region of 331 amino acid residues. Pro and structure gene of TGase were cloned into the yeast shuttle vector pYAEG-TER and then used to transform Saccharomyces cerevisiae 2805. Expression of mTGase in recombinant was confirmed with Northern hybridization and the maximal activity of TGase was shown 26 mU/ml.

• Applied Biological Chemistry
• /
• v.37 no.6
• /
• pp.456-462
• /
• 1994

Lysozyme-dextran hybrids were prepared by incubated storage at $60^{\circ}C$ and 80% relative humidity for 16 days. The emulsifying properties of the hybrids were about 14 times higher than those of native lysozyme and were about 3 times higher than those of commercial emulsifiers. Lytic activity of the hybrids remained about 83% that of native lysozyme when mesured against Micrococcus lysodeikticus as a substrate. The excellent emulsifying properties of the hybrids were maintained even at pH 3 and were further improved at pH 10. The emulsifying properties of the hybrids were greatly improved by preheating the hybrids at $100^{\circ}C$. In addition the lysozyme-dextran hybrids showed an antimicrobial effect on Gram-negative bacteria.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.04a
• /
• pp.99.2-99
• /
• 2003

미강은 미곡처리장에서 발생하는 도정부산물이지만 비타민 E, 식이섬유, 오리자놀, 불포화지방산 등 다양한 유효성분들이 함유되어 있고, 콜레스테롤 상승억제효과를 비롯한 여러 가지 생리적 효과를 지니고 있는 것으로 알려지고 있으며, 미국에서는 오래 전부터 미강을 빵, 쿠키, 스낵 등의 baked product에 적용시켜 건강식품을 제조하고 있으나 국내에서는 극히 일부가 미강유 제조에 이용되고 있을 뿐 대부분이 사료로 이용되고 있는 실정이다. 본 연구에서는 쌀의 도정에 의해 영양학적으로 손실된 쌀밥의 영양을 강화하고 쌀밥의 저장성을 향상시킬 목적으로 밥물에 미강 ethanol 추출물을 첨가하여 취반하고 쌀밥의 품질특성 및 저장성을 측정하였다. 미강 5~15g 상당량의 추출물과 지방산에스테르 혼합물의 첨가에 의한 쌀밥의 관능적 특성은 전체적으로 기호도, 맛, 향기 면에서 우수한 평점을 얻었으며 조직감에서도 상당히 높은 평점을 얻었다. 색도, 산도, 총세균수의 측정의 결과에 의한 쌀밥의 저장안정성은 3$0^{\circ}C$에서 저장 중, 대조구에서는 3일만에 변질이 되었으나 미강추출물 첨가구에서.는 4~수일간 변질이 지연되어 첨가 농도에 따라 미강추출물의 쌀밥 저장성이 증가되는 것으로 나타났다. 미강추출물을 표준 토코페놀과 비교하여 DPPH 라디컬 소거능에 의한 항산화 활성은 상당한 수준의 값을 나타냈다. 본 연구를 통해 미강추출물의 기능성 검토와 함께 쌀밥의 풍미개선을 위한 제품개발과 쌀 소비 촉진 효과가 기대된다.

• Korean Journal of Microbiology
• /
• v.39 no.2
• /
• pp.102-107
• /
• 2003

With the enrichment culture technique, bacterial strains which degrade diesel oil were isolated from soil contaminated with diesel oil. One of the isolates named GENECO 1 showed the highest activity for emulsification of diesel oil as well as the highest growth rate. This strain, GENECO 1, was identified as a Pseudomonas sp. based on its biochemical, physiological characteristics and 16S rDNA sequences. The optimal cultural conditions for cell growth and oil emulsifying activity of its culture were as follow; $30^{\circ}C$ for temperature, 7.0 for pH. Diesel oil degradation was analysed by the gas chromatography. More than 95% of 1% treated diesel oil were converted into a form no longer extractable by mixed organic solvents after 96 hours incubation.