• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.675-683
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• 2016

One osmotolerant strain from among 44 yeast isolates was selected based on its growth abilities in media containing high concentrations of sucrose. This selected strain, named SK-ENNY, was identified as Meyerozyma guilliermondii by sequencing the internal transcribed spacer regions and partial D1/D2 large-subunit domains of the 26S ribosomal RNA. SK-ENNY was utilized to produce high-fructose glucose syrup (HFGS) from sucrose-containing biomass. Conversion rates to HFGS from 310-610 g/l of pure sucrose and from 75-310 g/l of sugar beet molasses were 73.5-94.1% and 76.2-91.1%, respectively. In the syrups produced, fructose yields were 89.4-100% and 96.5-100% and glucose yields were 57.6-82.5% and 55.3-79.5% of the theoretical values for pure sucrose and molasses sugars, respectively. This is the first report of employing M. guilliermondii for production of HFGS from sucrose-containing biomass.

• 한국균학회지
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• 제45권4호
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• pp.336-344
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• 2017

본 연구에서는 우리나라 주요 산과 섬에서 분리한 비병원성 야생효모들 중 항염 효과가 우수했던 Meyerozyma guilliermondii YJ34-2와 Rhodotorula graminis YJ36-1의 무세포 추출물들을 제조하여 대식세포 계열 RAW 264.7 세포에 대한 이들의 NO 생성 저해활성과 세포독성을 조사하였다. NO 생성 저해활성은 농도 의존적으로 높아 M. guilliermondii YJ34-2와 R. graminis YJ36-1 무세포 추출물을 1,000 mg/mL 처리 시 각각 51.6%와 81.4%를 보여 가장 높았고 RAW 264.7 세포에 대한 세포 생존율도 1,000 mg/mL 처리시 각각 88.4% (${\pm}3.1$)와 77.1% (${\pm}0.3$)로 가장 높았다. 두 효모들의 무세포 추출물 처리에 따른 prostaglandin $E_2$ 생성량은 농도 의존적으로 감소하여 각각의 무세포 추출물을 1,000 mg/mL 처리했을 때, tumor necrosis factor $(TNF)-{\alpha}$ 생성량이 59.2 (${\pm}43.1$), 73.2 (${\pm}38.1$)%로 감소하였고 prostaglandin $E_2$의 생성량도 52.8 (${\pm}1.9$), 71.2 (${\pm}3.7$)%로 감소하여 이 두 효모들의 항균활성을 검증할 수 있었다. 두 효모들의 NO 생성 저해물질 최적 생산조건을 조사한 결과 M. guilliermondii YJ34-2를 yeast extract-peptone- dextrose (YPD) 배지에 접종하여 $30^{\circ}C$에서 24시간 배양하여 얻은 무세포 추출물이 가장 높은 51.6 (${\pm}0.3$)%의 NO 생성 저해율을 보였고 R. graminis YJ36-1를 YPD 배지에 접종하여 $25^{\circ}C$에서 24시간 배양하였을 때 81.4 (${\pm}1.3$)%의 가장 높은 NO 생성 저해활성을 보였다.

• 한국식품영양과학회지
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• 제45권10호
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• pp.1398-1405
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• 2016

꽃송이버섯에서 분리 선발한 Meyerozyma guilliermondii FM을 이용하여 꽃송이버섯 발효물을 제조하고 항산화 활성 및 면역조절 효과를 조사하였다. 꽃송이버섯 발효물 제조 시 M. guilliermondii FM은 유산균과 비슷한 생육능력을 보였으며, 5일째에는 오히려 높은 값을 나타내었다. 발효 후 총페놀 함량과 DPPH 라디칼 소거능은 유산균보다 유의적으로 높은 값을 나타내었다. 면역저하가 유발된 rat에서 비장 무게는 면역을 저하시킨 대조군보다 꽃송이버섯 비발효 추출물과 발효물 투여군에서 모두 유의적으로 증가하였다. 또한, 꽃송이버섯 발효물 투여에 따라 TNF-${\alpha}$, IL-2, IgE의 수치는 대조군보다 감소하였으며, IL-10은 증가하였으나 꽃송이버섯 비발효 추출물과 발효물 투여 사이의 유의적인 차이는 없었다. M. guilliermondii FM을 이용한 꽃송이버섯 발효물을 투여한 실험구는 혈액 내 백혈구 함량이 대조구 및 다른 처리구에 비하여 가장 높은 수치를 나타내었다.

• 한국균학회지
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• 제45권3호
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• pp.212-223
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• 2017

비병원성 야생효모들로부터 새로운 항염물질을 생산하고자 우리나라 주요 섬과 산에서 분리, 동정한 야생 효모들 중 비병원성 효모들의 무세포 추출물들을 제조하여 이들의 nitric oxide (NO) 생성 저해활성을 측정하였다. 182 균주 중 Metschnikowia reukaufii SY20-7, Rhodotorula ingeniosa SY1-1, Yarrowia lipolytica SY51-1, 51-3, Meyerozyma guilliermondii YJ34-2, Rhodotorula graminis YJ36-1, Rhodotorula nothofagi YJ1-1, YJ22-2, Metschnikowia koreensis UL32-1, Sporobolomyces carnicolor UL32-3 등 10 균주들의 무세포 추출물들이 30% 이상의 NO 생성 저해활성을 보였다. 이들 중 유포자효모들에서는 Rhodotorula graminis YJ36-1가 가장 높은 57.4%의 NO 생성 저해활성을 보였고 무포자효모들에서는 Meyerozyma guilliermondii YJ34-2가 47.0%로 가장높아 항염물질생산 우수효모로 최종 선발하였다. 선발된 야생효모들의 미생물학적 특성을 조사한 결과 Rhodotorula graminis YJ36-1 균주는 자낭포자와 위균사를 형성하였고 $25^{\circ}C$에서 잘 생육하였으며 Meyerozyma guilliermondii YJ34-2는 자낭포자와 위균사를 형성하지 않았고 $30^{\circ}C$, 5%의 NaCl 함유 YPD 배지에서도 잘 생육하였다. 또한, 두 효모 모두 pH 4.0~8.0에서 생육하였고 YM, PD, YPD, 비타민 무함유 배지 등에서 잘 생육하였다.

• Journal of Microbiology and Biotechnology
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• 제28권6호
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• pp.917-930
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• 2018

Intracellular synthesis of silver/silver chloride nanoparticles (Ag/AgCl-NPs) using Meyerozyma guilliermondii KX008616 is reported under aerobic and anaerobic conditions for the first time. The biogenic synthesis of Ag-NP types has been proposed as an easy and cost-effective alternative for various biomedical applications. The interaction of nanoparticles with ethanol production was mentioned. The purified biogenic Ag/AgCl-nanoparticles were characterized by different spectroscopic and microscopic approaches. The purified nanoparticles exhibited a surface plasmon resonance band at 419 and 415 nm, confirming the formation of Ag/AgCl-NPs under aerobic and anaerobic conditions, respectively. The planes of the cubic crystalline phase of the Ag/AgCl-NPs were confirmed by X-ray diffraction. Fourier-transform infrared spectra showed the interactions between the yeast cell constituents and silver ions to form the biogenic Ag/AgCl-NPs. The intracellular Ag/AgCl-NPs synthesized under aerobic condition were homogenous and spherical in shape, with an approximate particle size of 2.5-30nm as denoted by the transmission electron microscopy (TEM). The reaction mixture was optimized by varying reaction parameters, including temperature and pH. Analysis of ultrathin sections of yeast cells by TEM indicated that the biogenic nanoparticles were formed as clusters, known as nanoaggregates, in the cytoplasm or in the inner and outer regions of the cell wall. The study recommends using the biomass of yeast that is used in industrial or fermentation purposes to produce Ag/AgCl-NPs as associated by-products to maximize benefit and to reduce the production cost.

• Mycobiology
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• 제43권4호
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• pp.458-466
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• 2015

Oak tree death caused by symbiosis of an ambrosia beetle, Platypus koryoensis, and an ophiostomatoid filamentous fungus, Raffaelea quercus-mongolicae, has been a nationwide problem in Korea since 2004. In this study, we surveyed the yeast species associated with P. koryoensis to better understand the diversity of fungal associates of the beetle pest. In 2009, a total of 195 yeast isolates were sampled from larvae and adult beetles (female and male) of P. koryoensis in Cheonan, Goyang, and Paju; 8 species were identified by based on their morphological, biochemical and molecular analyses. Meyerozyma guilliermondii and Candida kashinagacola were found to be the two dominant species. Among the 8 species, Candida homilentoma was a newly recorded yeast species in Korea, and thus, its mycological characteristics were described. The P. koryoensis symbiont R. quercusmongolicae did not show extracelluar CM-cellulase, xylanase and avicelase activity that are responsible for degradation of wood structure; however, C. kashinagacola and M. guilliermondii did show the three extracellular enzymatic activities. Extracelluar CM-cellulase activity was also found in Ambrosiozyma sp., C. homilentoma, C. kashinagacola, and Candida sp. Extracelluar pectinase activity was detected in Ambrosiozyma sp., C. homilentoma, Candida sp., and M. guilliermondii. All the 8 yeast species displayed compatible relationships with R. quercus-mongolicae when they were co-cultivated on yeast extract-malt extract plates. Overall, our results demonstrated that P. koryoensis carries the yeast species as a symbiotic fungal associate. This is first report of yeast diversity associated with P. koryoensis.

• Journal of Microbiology and Biotechnology
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• 제26권12호
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• pp.2206-2213
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• 2016

Recently, several studies have revealed that commercial microbial identification systems do not accurately identify the uncommon causative species of candidiasis, including Candida famata, Meyerozyma guilliermondii, and C. auris. We investigated the accuracy of species-level identification in a collection of clinical isolates previously identified as C. famata (N = 38), C. lusitaniae (N = 1 2), and M. guilliermondii (N = 5) by the Vitek 2 system. All 55 isolates were re-analyzed by the Phoenix system (Becton Dickinson Diagnostics), two matrix-assisted laser desorption ionization-time of flight mass spectrometry analyzers (a Vitek MS and a Bruker Biotyper), and by sequencing of internal transcribed spacer (ITS) regions or 26S rRNA gene D1/D2 domains. Among 38 isolates previously identified as C. famata by the Vitek 2 system, the majority (27/38 isolates, 71.1%) were identified as C. tropicalis (20 isolates) or C. albicans (7 isolates) by ITS sequencing, and none was identified as C. famata. Among 20 isolates that were identified as C. tropicalis, 17 (85%) were isolated from urine. The two isolates that were identified as C. auris by ITS sequencing originated from ear discharge. The Phoenix system did not accurately identify C. lusitaniae, C. krusei, or C. auris. The correct identification rate for 55 isolates was 92.7% (51/55 isolates) for the Vitek MS and 94.6% (52/55 isolates) for the Bruker Biotyper, as compared with results from ITS sequencing. These results suggest that C. famata is very rare in Korea, and that the possibility of misidentification should be noted when an uncommon Candida species is identified.

• 한국미생물·생명공학회지
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• 제44권3호
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• pp.317-323
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• 2016

본 연구에서는 C. fermentati SI가 생산하는 isoflavone 배당체 가수분해 효소를 클로닝하여 염기 서열을 밝힌 뒤 P. pastoris X-33에 형질전환하여 재조합 효소의 과발현을 시켰고, 또한 재조합 isoflavone 가수분해 효소의 효소학적 특성을 조사하였다. 재조합 isoflavone 가수분해 효소의 분자량은 약 50.4 kDa이었으며, Meyerozyma guilliermondii ATCC 6260의 exo-1,3-β-glucanase와 96%로 가장 높은 homology를 나타내었다. exo-1,3-β-glucanase의 ORF는 pPICZA 벡터로 클로닝 후 P. pastoris X-33으로 형질전환을 하였으며, His6-tag을 이용하여 효소를 정제하였다. 정제된 효소는 citrate phosphate buffer pH 4.5에서 최적 활성을 나타내었으며, 효소의 최적 활성 온도는 40℃로 나타났다. 40℃이상에서는 효소의 활성이 급격하게 감소함을 확인 하였으며, pH 안정성을 조사한 결과 비교적 넓은 범위인 4−8 사이에서 80%이상의 활성을 유지하였다. 따라서, 재조합 효소의 과발현을 통해 isoflavone aglycone의 효율적인 생산에 이용할 수 있을 것으로 사료된다.