• Applied Biological Chemistry
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• 제34권2호
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• pp.130-133
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• 1991

재래식 메주의 23개 시료에 대해서 내부층과 외부층의 부위별로 산생성균수 및 총균수를 조사하고 이들 균주를 동정하였다. 산생성균은 내부층에 비하여 외부층에 많았고 각 부위에 있어서 호기성 산생성균보다 혐기성 산생성균이 많은 경향을 나타내었다. 호기성 산생성균 중 비호염성균 및 내염성균의 평균균수는 각각 $24{\times}10^6$ 및 $33{\times}10^5cell/g$였고 혐기성 산생성균 중 비호염성균 및 내염성균의 평균균수는 $10{\times}10^7$ 및 $58{\times}10^5cell/g$였다. 호기성 산생성균 2균주는 Micrococcus sp., 혐기성 산생성균 3균주는 Strepococcus sp., Pediococcs sp. 및 Lactobacillus sp., 호기성 일반세균 2균주는 Bacillus sp.으로 각각 동정되었다.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.821-827
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• 2008

The unicellular green alga Dunaliella salina is a halotolerant eukaryotic organism. Its halophytic properties provide an important advantage for open pond mass cultivation, since D. salina can be grown selectively. D. salina was originally described by E. C. Teodoresco in 1905. Since that time, numerous isolates of D. salina have been identified from hypersaline environments on different continents. The new Dunaliella strain used for this study was isolated from the salt farm area of the west coastal side of South Korea. Cells of the new strain were approximately oval- or pear-shaped (approximately $16-24\;{\mu}m$ long and $10-15\;{\mu}m$ wide), and contained one pyrenoid, cytoplasmatic granules, and no visible eyespot. Although levels of $\beta$-carotene per cell were relatively low in cells grown at salinities between 0.5 to 2.5 M NaCl, cells grown at 4.5 M NaCl contained about a ten-fold increase in cellular levels of $\beta$-carotene, which demonstrated that cells of the new Korean strain of Dunaliella can overaccumulate $\beta$-carotene in response to salt stress. Analysis of the ITS1 and ITS2 regions of the new Korean isolate showed that it is in the same clade as D. salina. Consequently, based on comparative cell morphology, biochemistry, and molecular phylogeny, the new Dunaliella isolate from South Korea was classified as D. salina KCTC10654BP.

• 한국균학회지
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• 제45권1호
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• pp.23-30
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• 2017

각종 나뭇잎들의 효모 분포특성을 알아보기 위하여 대전광역시 서부지역에 위치한 옥녀봉과 연자산의 나뭇잎들로부터 야생효모들을 분리, 동정하였고 이들로부터 국내 미기록 효모들을 선별하여 균학적 특성을 조사하였다. 옥녀봉의 나뭇잎 20점으로부터 15종 22균주의 야생효모를 분리, 동정하였고 Cryptococcus bestiolae가 5주로 가장 많이 분리되었다. 또한 연자산 나뭇잎 20점에서는 모두 12종 24균주의 야생효모를 분리하였고 Aureobasidium pullulans가 8주로 가장 많았다. 옥녀봉과 연자산에서 분리한 야생효모 46균주 중에서 6종(Cryptococcus kuetzingii JSL508, Cryptococcus vishniacii JSL509, Dioszegia takashimae JSL510, Plowrightia periclymeni JSL514, Erythrobasidium hasegawianum JSL0193, Rhodotorula nothofagi JSL0196)을 국내에서 보고되지 않은 미기록 효모들로 최종 선별하였다. 이들의 균학적 특성을 조사한 결과 E. hasegawianum JSL0196은 자낭포자와 의균사를 형성하지 않았다. D. JSL510 외 모든 미기록 효모들은 내염성 또는 호염성이었고, C. JSL508과 D. JSL510은 $37^{\circ}C$에서 생육하는 고온성 효모들이었다.

• Journal of Microbiology and Biotechnology
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• 제29권7호
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• pp.1124-1136
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• 2019

Salinity is one of the major abiotic stresses that cause reduction of plant growth and crop productivity. It has been reported that plant growth-promoting bacteria (PGPB) could confer abiotic stress tolerance to plants. In a previous study, we screened bacterial strains capable of enhancing plant health under abiotic stresses and identified these strains based on 16s rRNA sequencing analysis. In this study, we investigated the effects of two selected strains, Bacillus aryabhattai H19-1 and B. mesonae H20-5, on responses of tomato plants against salinity stress. As a result, they alleviated decrease in plant growth and chlorophyll content; only strain H19-1 increased carotenoid content compared to that in untreated plants under salinity stress. Strains H19-1 and H20-5 significantly decreased electrolyte leakage, whereas they increased $Ca^{2+}$ content compared to that in the untreated control. Our results also indicated that H20-5-treated plants accumulated significantly higher levels of proline, abscisic acid (ABA), and antioxidant enzyme activities compared to untreated and H19-1-treated plants during salinity stress. Moreover, strain H20-5 upregulated 9-cisepoxycarotenoid dioxygenase 1 (NCED1) and abscisic acid-response element-binding proteins 1 (AREB1) genes, otherwise strain H19-1 downregulated AREB1 in tomato plants after the salinity challenge. These findings demonstrated that strains H19-1 and H20-5 induced ABA-independent and -dependent salinity tolerance, respectively, in tomato plants, therefore these strains can be used as effective bio-fertilizers for sustainable agriculture.

• 한국미생물·생명공학회지
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• 제47권1호
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• pp.105-115
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• 2019

Saline or alkaline condition in soil inhibits growth of most crop plants and limits crop yields in many parts of the world. Augmenting an alkaline soil with alkali-tolerant bacteria capable of promoting plant growth can be a promising approach in expanding fertile agricultural land. Near-shore environments of Dokdo Island, a remote island located in the middle of the East Sea, appear to have patches of seawater-influenced haloalkaline soil that is unsupportive for growth of conventional plants. To exploit metabolic capacities of alkali-tolerant bacteria for promoting plant growth in saline or alkaline soils, we isolated of alkali-tolerant bacteria from near-shore soil samples in Dokdo and investigated properties of the isolates. Alkali-tolerant bacteria were selectively cultivated by inoculating suspended and diluted soil samples on a plate medium adjusted to pH 10. Fifty colonies were identified based on their $GTG_5$-PCR genomic fingerprints and 16S rRNA gene sequences. Most isolates were affiliated to alkali-tolerant and/or halotolerant genera or species of the phyla Firmicutes (68%), Proteobacteria (30%) and Actinobacteria (2%). Unlike the typical soil bacterial flora in the island, alkali-tolerant isolates belonged to only certain taxa of terrestrial origin under the three phyla, which have traits of plant growth promoting activities including detoxification, phytohormone production, disease/pest control, nitrogen-fixation, phosphate solubilization or siderophore production. However, Firmicutes of marine origin generally dominated the alkali-tolerant community. Results of this study suggest that haloalkaline environments like Dokdo shore soils are important sources for plant growth promoting bacteria that can be employed in bio-augmentation of vegetation-poor alkaline soils.

• Journal of Species Research
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• 제8권2호
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• pp.197-214
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• 2019

The taxonomic hierarchy of the phylum Proteobacteria was assessed, after which the isolation and classification state of Proteobacteria species with valid names for Korean indigenous isolates were studied. The hierarchical taxonomic system of the phylum Proteobacteria began in 1809 when the genus Polyangium was first reported and has been generally adopted from 2001 based on the road map of Bergey's Manual of Systematic Bacteriology. Until February 2018, the phylum Proteobacteria consisted of eight classes, 44 orders, 120 families, and more than 1,000 genera. Proteobacteria species isolated from various environments in Korea have been reported since 1999, and 644 species have been approved as of February 2018. In this study, all novel Proteobacteria species from Korean environments were affiliated with four classes, 25 orders, 65 families, and 261 genera. A total of 304 species belonged to the class Alphaproteobacteria, 257 species to the class Gammaproteobacteria, 82 species to the class Betaproteobacteria, and one species to the class Epsilonproteobacteria. The predominant orders were Rhodobacterales, Sphingomonadales, Burkholderiales, Lysobacterales and Alteromonadales. The most diverse and greatest number of novel Proteobacteria species were isolated from marine environments. Proteobacteria species were isolated from the whole territory of Korea, with especially large numbers from the regions of Chungnam/Daejeon, Gyeonggi/Seoul/Incheon, and Jeonnam/Gwangju. Most Halomonadaceae species isolated from Korean fermented foods and solar salterns were halophilic or halotolerant. Air-borne members of the genera Microvirga, Methylobacterium, and Massilia had common characteristics in terms of G+C content, major respiratory quinones, and major polar lipids.

• 한국균학회지
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• 제48권4호
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• pp.457-473
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• 2020

본 연구에서는 국내 기수 환경의 물과 토양에서 균류의 다양성을 확인하기 위해 을숙도, 금강하구둑, 순천만습지, 대호방조제, 신두리사구 및 부남방조제 총 6지점의 현장조사 및 시료를 채집하였다. 현장에서 여과한 담수시료와 담수퇴적물로부터 곰팡이를 순수분리하여 PDA배지에 접종한 후 25℃에서 배양하였다. 기수역 시료에서 순수분리된 균주는 총 173균주로 ITS 부분을 분석하여 속 수준으로 동정하였다. 분리 동정된 균주를 다양성 지수를 이용하여 분석하였다. 분리된 균류는 Pleosporales, Eurotiales, Capnodiales, Hypocreales, Polyporales, Saccharomycetales, Agaricales, Glomerellales, Mucorales, Dothideales, Russulales, Xylariales, Sordariales, Myrmecridiales, Tubeufiales, Onygenales, Cantharellales, Amphisphaeriales 목에 속하며 Cladosporium속이 20%로 가장 우점하며, 그 다음은 Penicillium (19%), Fusarium (5%)의 순서로 많이 분포하였다. Sarocladium kiliense NNIBRFG3280와 Fusicolla merismoides NNIBRFG23708를 국내 기수환경에서 발굴하였으며, 이를 국내 미기록종으로 보고하고자 한다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2023년도 춘계학술대회
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• pp.32-32
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• 2023

Cadmium and salt exposure to crops is considered vulnerable for production as well as consumption. To address these challenges, the current study aimed to mitigate the toxicity induced by salt and cadmium in soybean plants through the application of bacterial strain Bacillus safensis KJW143 isolated from the rhizosphere of oriental melon..The bioassay analysis revealed that KJW143 is a highly salt-tolerant and cadmium-resistant (Cd) strain with an innate ability to produce melatonin, gibberellin (GA3), Indole-3-Acetic Acid (IAA), and organic acids (i.e., acetic, succinic, lactic, and propionic acids). Soybean plants at 20 days old were treated with KJW143 in a different form (pellet, broth, and together) and their effect on plant performance was investigated. Inoculation with KJW143enhanced plant biomass and growth attributes in soybean plants compared to the control (non-treated). In particular, we observed that only pellet-treated showed 65%, 27.5%, and 28.7% increase in growth (shoot fresh weight) compared to broth, broth with pellet, and control. In addition, bacterial strain KJW143 treatment (only pellet) modulated the physiochemical apparatus of soybean plants by increasing glucose (390%), arabinose (166%), citric acid (22.98%) and reducing hydrogen peroxide (29.7%), catalase (32.1%), salicylic acid (25.6%) compared to plants with combined stressed plants (cd and salinity). These findings suggest that bacterial strain KJW143 could be usedas a biofertilizer to minimize the probable risk of heavy metal and salinity stress on crops.

• 한국균학회지
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• 제47권1호
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• pp.51-61
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• 2019

우리나라 금강의 물과 주변 토양에 분포하는 야생 효모들의 종 다양성을 확립하고자 세종특별자치시 불티교와 햇무리교를 흐르는 금강 중류의 물과 주변 토양에서 야생 효모들을 분리, 동정하였고 이들 중 국내 미기록 효모들을 선별하여 이들의 균학적 특성을 조사하였다. 세종시 불티교 밑의 물과 주변 토양들로부터 32종, 37균주의 야생 효모들을 분리, 동정하였다. 이들 중 Holtermanniella takashimae SW048 (NNIBRFG9314), Cystofilobasidium infirmominiatum SW013 (NNIBRFG9310), Mrakia cryoconite SW015(NNIBRFG9316), Pichia sporocuriosa SW085(NNIBRFG9326)와 Cryptococcus aspenensis SW008 (NNIBRFG9309) 5균주들을 국내 미기록 효모 균주들로 최종 선별하였고, 이들은 구형-난형으로 출아에 의해 영양증식을 하였다. M. cryoconite SW015 외 모두 자낭포자를 형성하였고, P. sporocuriosa SW085 와 C. aspenensis SW008 균주는 20% 포도당을 함유한 YPD 배지에서도 생육하는 내당성 야생 효모들이었다. 또한, 세종시 햇무리교의 물과 주변 토양시료에서 모두 8종 26균주의 야생 효모들을 분리, 동정하였고 이들 야생 효모들 중 Occultifur kilbournensis HB060 (NNIBRFG9317), Sampaiozyma vanillica HB014 (NNIBRFG9332), Xenoramularia neerlandica HB039 (NNIBRFG9335), Candida norvegica HB315 (NNIBRFG9306), C. melibiosicaHB316 (NNIBRFG9305), C. quercuum GB014 (NNIBRFG9307)와 C. succiphila GB015 (NNIBRFG9308) 7균주 국내 미기록 효모들로 분류되었다. O. kilbournensis HB060와 X. neerlandica HB039는 자낭포자와 의균사를 형성하지 못하였고 C. norvegica HB315는 5 % NaCl를 함유한 YPD 배지에서 생육하는 내염성을 보였다. 본 연구결과는 앞으로 금강의 야생 효모 종 다양성 확립에 귀중한 자료로 활용될 것이다.

• 미생물학회지
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• 제35권4호
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• pp.289-295
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• 1999

Dunaliella bardawil의 적절한 생장과${\beta}$-carotene의 효과적인 축적 조건을 확립하기 위하여 염 농도, pH, 광량, 교반속도, 오존처리, 과산화수소 첨가 등의 영향을 비교하였고, 식용 식물성 기름을 이용한 ${\beta}$-carotene의 추출조건을 비교하였다. D. bardawil의 비생장 속도는 1N NaCl, pH 8.0 광량 80${\mu}$$E/\m^2/s$ , 70rpm 으로 배양 시에 0.168/hr로 최대를 나타냈다. 흰색 형광등을 250${\mu}$$E/\m^2/s$ 로 조사한 경우 ${\beta}$-carotene isomer 축적은 cis isomer가 trans isomer에 비해 높은 증가율을 보였다. ${\beta}$-carotene의 축적을 위하여 50${\mu}$M 과산화수소를 배양 2일 경과 후에 첨가한 경우 대조군의 축적율이 150${\mu}$g/ml인데 비해 324${\mu}$g/ml로, 200ppb로 2시간 오존 처리했을 때 약 1.8배 증가한 270${\mu}$g/ml이었다. 식용기름에 의한 37${\circ}C$에서의 추출효율은 올리브유, 참기름, 미강유, 옥수수유, 대두유의 순서로 나타났으며, 올리브유를 수층 부피의 9배로 첨가하고 50${\circ}C$에서 1시간 동안 sonication한 결과 96.95의 추출효율을 나타내었다.