• Journal of Microbiology and Biotechnology
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• 제28권4호
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• pp.571-578
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• 2018

Biofuel production using lignocellulosic biomass is gaining attention because it can be substituted for fossil fuels without competing with edible resources. However, because Saccharomyces cerevisiae does not have a ${\text\tiny{D}}$-xylose metabolic pathway, oxidoreductase or isomerase pathways must be introduced to utilize ${\text\tiny{D}}$-xylose from lignocellulosic biomass in S. cerevisiae. To elucidate the biochemical properties of xylose isomerase (XI) from Piromyces sp. E2 (PsXI), we determine its crystal structure in complex with substrate mimic glycerol. An amino-acid sequence comparison with other reported XIs and relative activity measurements using five kinds of divalent metal ions confirmed that PsXI belongs to class II XIs. Moreover kinetic analysis of PsXI was also performed using $Mn^{2+}$, the preferred divalent metal ion for PsXI. In addition, the substrate-binding mode of PsXI could be predicted with the substrate mimic glycerol bound to the active site. These studies may provide structural information to enhance ${\text\tiny{D}}$-xylose utilization for biofuel production.

• 한국식품영양학회지
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• 제10권3호
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• pp.360-364
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• 1997

멥쌀식혜에 Saccharomyces cerevisae를 가해 28$^{\circ}C$에서 10일간 발효시켜서 식혜주를 제조하였다. TLC 및 HPLC 분석 결과 발효에 따라 글루코오스는 하루, 말토오스는 4일, 말토트리오스는 6일까지만 존재하였다. 그러나, 분자량이 큰 말토올리고당과 한계덱스트린은 발효되지 않았다. 에탄올은 6.5%를 나타냈다. 식혜주의 아미노산 함량은 2.9$\mu$mol/ml, 단백질 함량은 457$\mu\textrm{g}$/ml를 나타냈다. pH는 3.67, 산도는 3.1ml를 나타냈다. 한계덱스트린은 1H-NMR로 분석 결과 식혜에 존재하는 것과 구조상 변화가 없었다. $\alpha$-1,4-결합에 대한 $\alpha$-1,6-결합의 비율도 5.6:1을 나타냈다. 관능검사 결과, 맛은 와인과 비슷하였다.

• 한국식품저장유통학회지
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• 제23권4호
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• pp.591-598
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• 2016

본 연구에서는 토마토 농축액을 이용한 무가당 알코올 발효를 통해 가장 우수한 균주를 선발하고자 하였다. 토마토 와인을 제조할 토마토 농축액($25^{\circ}Brix$)의 수분 함량은 67.33%, 조단백질 함량은 1.90%, 조지방 함량은 0.03%, 조회분 함량은 0.02%, 가용성 무질소물은 30.72%로 나타났고, 유리당은 fructose, glucose가 함유되어 있었고, 유리아미노산이 총 19종으로 glutamic acid가 814.7 mg/100 g로 가장 많이 함유되어 있었다. 알코올 함량은 발효 3일째 가장 높은 알코올 함량을 보였으며, 사용 균주 중 사용 균주 중 TWB(S. cerevisiae ICVD-47)는 8.20%로 가장 높은 알코올 함량을 나타내었고, 당도는 발효 4일차에서도 TWB(S. cerevisiae ICVD-47)는 13.25로 가장 낮은 잔류당 함량을 나타내었고, 각 균주의 당도는 $13.25{\sim}13.45^{\circ}Brix$로 비슷한 경향을 나타내었다. 환원당은 4일차에서 28.37~28.48 mg/mL의 값을 나타내어 알코올 발효 균주에 따른 차이가 없는 것으로 나타났다. pH는 4.31~4.55의 값을 나타내어 균주에 따른 pH의 차이는 없는 것으로 나타났다. 총산은 사용된 균주 모두 1일차에서 4일차까지 큰 변화가 없는 것으로 나타났다. 색도 L, a, 및 b 값은 사용된 균주 간에는 차이가 없는 것으로 나타났다. 이상의 결과 토마토 농축액 알코올 발효에 적합한 균주는 알코올 생성량이 높고, 낮은 잔류당 함량을 가진 TWB(S. cerevisiae ICVD-47)가 가장 좋은 것으로 판단된다.

• 미생물과산업
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• 제12권2호
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• pp.30-35
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• 1986

Almost all of the aerobic organisms contain citric acid cycle (or, tricarboxylic acid cycle). This cycle is involved both in energy metabolism and biosynthetic reactions; generation of NADH which derives the synthesis of chemical energy, ATP, and provision of intermediates needed for the biosynthesis. Because of its importance in the cellular metabolism, the regulation of the TCA cycle and its component enzymes has been extensively studied by many biologists (7,28). Citrate synthase is resposible for the initial step of the cycle and has been recognized as the rate limiting step (14,121,26). Understanding of the mechanism of the expression of citrate synthase should be a key step for the elucidation of the regulation of the TCA cycle in the cell metabolism.

• 한국식품영양과학회지
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• 제21권4호
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• pp.377-380
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• 1992

To produce economically important acid with pear juice, an acetic acid bacterium was selected from many isolated acetic acid bacteria. The alcohoic fermentation was conducted by inoculating pear juice with Saccharomyces cerevisiae ATCC 4124, and then the pear vinegar was prepared by batch cultivation in flaskes with the isolated Acetobacter sp. The optimum conditions for high yield of acetic acid were studied experimentally in the batch shake flask . For seed purposes the Acetobactor sp. was cultivated for 2 -days and transferred to the acid production medium . Optimum alcohol concentration, initial acidity and temperature for the acid production were 8.0% , 2.0% and 28$^{\circ}C$, respectively. Under the same conditions, the addition of yeast extract (1%) was observed to produce relatively high yield of acetic acid.

• 한국미생물·생명공학회지
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• 제38권2호
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• pp.129-135
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• 2010

본 논문은 한국인삼의 추출물 제조 시 부수적으로 생산되는 유출액에 의한 환경오염을 방지하고 나아가 이들로부터 고부가가치의 생리활성물질을 유출액에서 생육이 우수한 균류로부터 생산한 논문이다. 유출액에서 생육이 좋았던 Hansenula anomala KCCM 11473으로부터 5'-ribonucleotide 생산 최적 조건은 세포현탁액의 pH를 5.0으로 하고 $55^{\circ}C$에서 24시간 자기소화 시키는 조건이다. 또한 생육이 좋았던 Saccharomyces cerevisiae는 유출액 배지에서 배양 중 약리 성분이 Ginsenoside-Rg3를 고형물 1 g당 0.033 mg을 생성하였다. Mucor miehei KCTC 6011을 유출액에 접종하여 $25^{\circ}C$에서 84시간 배양했을 때 균체 건물 g당 120 mg의 키토산을 생성하였다.

• 한국환경보건학회지
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• 제28권5호
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• pp.28-34
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• 2002

Antigenicity of Rhodotrula rubra isolated from pulmonary tissue of pulmonary tuberculosis patients was studied by means of agglutination reaction with R. rubra whole cell antiserum. And the serological reactivity of crude polyfac charide from R. frubra, Candida albicans, Candida tropicalis, Candida, glabrata, and Saccharomyces cerevisiae ATCC 26603 with antiserum to R. rubra whole cell was studied by means of immunodiffusion test. R. rubra showed stationary phase after 48h when it was cultured in GYEP broth. While agglutinogen titer was 1:64 at lag phase, agglutinogen titer was 1 :256 after 20h. After growth of R. rubra on different 11 media, nutritional environment showed similar agglu-tination reartivity. The agglutinogen titer of C. albicans, C. tropicalis, C. giabrata, which were isolated from patient's expectoration, to R. rubra antiserum by means of agglutination reaction were 1:16, respectively. But, Sacch. cervisiae ATCC26603 was negative. Those results were lower than that of R. rubra agglutinogen titer 1:256. As a result of immu-nodiffusion test with crude polysaccharide extracted from cell wall of R. rubra, C. albicans, C. tropicalis, C. glabrata, Sacch. cervisiae ATCC26603, precipitin line was found only with R. rubra, of which antibody titer was 8.

• Mycobiology
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• 제39권1호
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• pp.33-39
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• 2011

Wild yeasts on the surface of various fruits including grapes were surveyed to obtain yeast strains suitable for fermenting a novel wine with higher alcohol content and supplemented with rice starch. We considered selected characteristics, such as tolerance to alcohol and osmotic pressure, capability of utilizing maltose, and starch hydrolysis. Among 637 putative yeast isolates, 115 strains exhibiting better growth in yeast-peptone-dextrose broth containing 30% dextrose, 7% alcohol, or 2% maltose were selected, as well as five ${\alpha}$-amylase producers. Nucleotide sequence analysis of the 26S rDNA gene classified the strains into 13 species belonging to five genera; Pichia anomala was the most prevalent (41.7%), followed by Wickerhamomyces anomalus (19.2%), P. guilliermondii (15%), Candida spp. (5.8%), Kodamaea ohmeri (2.5%), and Metschnikowia spp. (2.5%). All of the ${\alpha}$-amylase producers were Aureobasidium pullulans. Only one isolate (NK28) was identified as Saccharomyces cerevisiae. NK28 had all of the desired properties for the purpose of this study, except ${\alpha}$-amylase production, and fermented alcohol better than commercial wine yeasts.

• KSBB Journal
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• 제28권5호
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• pp.315-318
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• 2013

Ethanol fermentations were performed using separate hydrolysis and fermentation (SHF) processes with monosaccharides from pretreated seaweed, Eucheuma spinosum as the biomass. The pretreatment was carried out with 11% (w/v) seaweed slurry and 150 mM $H_2SO_4$ at $121^{\circ}C$ for 40 min. Enzyme hydrolysis after $H_2SO_4$ pretreatment was performed with Celluclast 1.5 L at $45^{\circ}C$ for 24 h. Five % active charcoal were added to hydrolysate to removed 5-hydroxy methylfurfural. Ethanol fermentation with 11% (w/v) seaweed hydrolysate was performed for 72~96 h using Kluyvermyces marxianus, Pichia stipits, Saccharomyces cervisiae and Candida tropicalis. Ethanol concentration was reached to 18 g/L by K. marxianus, 16 g/L by P. stipitis, 15 g/L by S. cerevisiae and 10 g/L by C. tropicalis, respectively. The ethanol yield from total monosugar was obtained 0.50 and ethanol productivity was obtained 0.38 g/L/h by K. marxianus.

• Journal of Animal Science and Technology
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• 제52권2호
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• pp.117-124
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• 2010

본 연구는 균상재배 느타리버섯부산물(SMS)의 반추동물 조사료원으로서의 가치를 평가하기 위하여 in situ 반추위 소실율 및 면양을 이용한 in vivo 영양소 소화율, 체내 질소이용성 및 섭취행동 패턴을 평가하였다. SMS에 당밀 5% (w/w, 건물기준), 유산균(Lactobacillus plantarum) 0.5% (v/w) 그리고 효모 (Saccharomyces cerevisiae) 0.5% (v/w)를 첨가하여 30일간 혐기발효 시킨 후 반추위캐뉼라가 장착된 평균체중 620 kg Holstein 육우 2두를 이용하여 in situ 소실율을 평가하였다. 면양대사실험은 평균체중 48kg의 숫 면양 6두 이용하여 $3{\times}3$ 라틴방각법으로 하였다. 대조구는 볏짚 100%를, 처리구는 볏짚의 25%와 50%를 생균발효 SMS로 각각 대체 급여하였다. 균상재배 버섯부산물의 반추위 in situ DM 및 NDF 이용성은 생균발효처리에 의해 개선되었다(P<0.001). 생균발효 SMS를 볏짚의 25% 및 50% 대체하여 면양에게 급여하였을 때, 단백질과 섬유소(NDF, ADF, CF) 소화율은 감소하였으나 (P<0.05), 조회분 소화율은 증가하였으며(P<0.001), 면양체내 단백질 축척량은 차이가 없었다(P>0.05). 볏짚을 생균발효 SMS로 대체 급여함에 따라 면양의 반추시간은 평균 28% 감소하였다(P<0.05). 생균발효 SMS는 볏짚의 76% 수준의 에너지가를 보였다. 결과적으로, 균상재배 느타리버섯부산물은 유지목적의 반추동물 조사료원으로서 보다 적합한 것으로 사료되었다.