• 한국미생물·생명공학회지
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• 제16권4호
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• pp.327-333
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• 1988

대장균을 이용한 재조합 인체 인터루킨-2(IL_2) 생산의 최적화를 위하여 발효조건이 세포성장과 IL-2의 생산 및 재조합 세포의 안정성 등에 미치는 영향을 조사하였다. 복합배지의 경우에는 yeast extract, peptone, corn steep liquor 등이 재조합 세포성장에 좋은 효과를 나타내었다. 재조합 세포의 안정성은 IL-2 발현 억제 조건(3$0^{\circ}C$)에서는 안정하게 유지되었으나 IL-2 생산조건(42$^{\circ}C$)에서는 selection pressure를 주었을 때조차도 현격하게 감소함을 알 수 있었다. 한편 배양배지에 항생제를 첨가한 경우에도 안정성 유지에는 별로 도움이 되지 못하고 세포성장만 억제됨을 알 수 있었다. 유전자의 발현은 대수 증식 중기에서 유도했을 때가 IL-2 생산에 가장 좋은 것으로 나타났으며 IL-2 생산은 세포성장과 플라스미르내의 다른 유전자들의 발현을 상당히 저해시킴을 알 수 있었다.

• 한국식품과학회지
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• 제38권5호
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• pp.642-647
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• 2006

저알콜 딸기발효주 제조에 필요한 최적발효조건 설정을 위하여 발효에 적합한 효모를 선발하고, 딸기착즙액의 살균방법을 비교하였으며, 발효 중 이화학적 특성의 변화를 조사하였다. 딸기는 매향과 육보 품종을 사용하였으며, 이들은 각각 pH 3.77 및 3.69, 가용성 고형분 함량 9.8 및 9.3%, 총산 함량 0.74 및 0.69%의 이화학적 특성을 가졌다. 6종의 효모를 대상으로 발효시험을 한 결과 Wg-15 와 Sc-51 효모의 알콜생성능력이 우수하였다. 딸기에 있는 잡균을 제거하기 위하여 $K_2S_2O_5$(200 ppm) 및 열처리($85^{\circ}C$, 10 min) 시험을 비교한 결과 알콜생성량(7.1-7.2%)과 가용성 고형분 함량(5.6-5.8%)이 비슷하였으며, Wg-15와 Sc-51 효모 사이에 유의적 차이는 관찰되지 않았고, 발효주의 향에서 열처리구가 약간 좋은 것으로 나타났다. 초기 가용성 고형분 함량을 12, 14 및 16%로 조정하여 $26^{\circ}C$ 에서 8일간 발효한 결과 발효 2일째 까지 대부분의 알콜이 생성되었으며, 알콜함량은 각각 5.1 6.0-6.2, 7.5-7.7%, 가용성 고형분 함량은 각각 3.9-4.3, 4.1-4.3, 5.0-5.3%를 나타냈고, Wg-15 와 Sc-51 효모 사이에 차이는 관찰되지 않았다. 알콜함량 7% 정도의 딸기발효주를 제조하기 위해서는 매향 또는 육보 품종을 사용하여 설탕으로 가용성 고형분 함량을 16%로 보당하고, 착즙액에 대해 $85^{\circ}C$에서 10min 열처리한 후 Wg-15 또는 Sc-51 효모를 사용하여 $26^{\circ}C$에서 8일간 발효하는 것이 바람직하였다.

• KSBB Journal
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• 제25권4호
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• pp.401-407
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• 2010

We established a strategy for bioethanol production using the hydrolysate of rape stem, in which the inhibitor cocktail was added intentionally. The final goal of this study was to circumvent the detoxification process when the hydrolysate of lignocelluloisic biomass contained the toxic substances in high concentration. When six yeast strains were examined, Sacchromyces cerevisiae ATCC 96581 and Pichia stipitis CBS 7126 were relatively resistant to inhibitor cocktail. Then, using strains 96581 and 7126, we designed a process strategy for bioethanol production, assuming that the concentration of toxic substance in the hydrolysate of rape stem was remarkably high. When strains 96581 and 7126 were inoculated simultaneously, it was observed that strain 7126 produced bioethanol as well as strain 96581, although the concentration of inhibitor cocktail was 18.2% (v/v). Finally, throughout this co-cultivation of strains 96581 and 7126, bioethanol was produced about 6.0 (g/L), and bioethanol yield reached at 0.4 (g-bioethanol/g-reducing sugar) (78.4% of theoretical value).

• Journal of Microbiology and Biotechnology
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• 제1권3호
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• pp.151-156
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• 1991

In order to construct a yeast strain having high ethanol tolerance together with good lactose fermentation ability, the protoplast fusion using Saccharomyces cerevisiae STV 89 and Kluyveromyces fragilis CBS 397 was carried out. Auxotrophic mutants of K. fragilis were obtained as a selection marker by treatment of ethylmethane sulfonate. The best mutant for protoplast fusion was selected based on the capabilities of ${\beta}-galactosidase$ production and lactose fermentation. The protoplast fusion using polyethylene glycol and calcium chloride solution led to the fusion frequence of $3{\times}10^{-6}$ and a number of fusants were obtained. Among these fusants, a fusant F-3-19 showed the best results in terms of ethanol tolerance, ${\beta}-galactosidase$ activity and lactose fermentation. The performance of lactose fermentation and ethanol tolerance by this fusant were better than those of K. fragilis. Study on the ethanol tolerance having relation to fatty acid composition and intracellular ethanol concentration revealed that the fusant F-3-19 had a higher unsaturated fatty acids content and accumulated less amount of intracellular ethanol compared with a parent of K. fragilis.

• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.328-333
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• 2008

A series of pep tides binding to the HCV NS5B polymerase was selected from phage display peptide libraries. A conserved motif of Ser-Arg-X-Arg/Leu was identified among the selected peptides, and Pep2 (Trp-Ser-Arg-Pro-Arg-Ser-Leu) was chosen for further characterization. The binding of Pep2 to HCV NS5B in vivo was shown by a yeast two-hybrid assay and by subcellular colocalization analysis using immunofluorescence confocal microscopy. The in vitro interaction was also confirmed by GST pulldown assay. The replication of the HCV 1b subgenomic replicon was efficiently inhibited by the presence of the peptide. By using a subtractive biopanning against Pep2, the binding site of the peptide was mapped at the pocket of Pro388 to Pro391 in the thumb subdomain of the polymerase. A yeast two-hybrid analysis using Pro388Ala and Pro391Ala mutants of NS5B confirmed the binding.

• 농업과학연구
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• 제2권2호
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• pp.463-468
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• 1975

(1) 당밀 주정증류 폐액를 배지(培地)로 하여 폐액류로(流路)의 퇴적토양과 그밖의 토양으로부터 224주(株)의 균주(菌株)를 분리(分離)하고 진탕 배양(培養)하여 균주(菌株)의 생육도(生育度)가 우수한 균주(菌株)를 선정하였다. (2) 선정(選定)된 2균주(菌株)는 Lodder의 A taxonomic study에 의하여 각각(各各) Candida brumpii와 Candida ciferrii로 동정(同定) 되었다.

• 대한수의학회지
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• 제40권4호
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• pp.701-706
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• 2000

This study was carried out to select the lactic acid bacteria(Lactobacillus, Streptococcus and Bifidobacterium) and yeast for probiotic use in pigs. Acid-tolerant 536 strains were isolated from the feces of 30 pigs. To select useful strains, the first screened strains were treated with strong acid solution(pH 2.5 to 3.0) for 3 hours and subsequentely treated with the anaerobic diluent solution containing 0.15% Oxgall for 3 hours. Among these strains, 151 strains showed strong tolerance to both acid and bile. Lactobacillus and Streptococcus tolerant to the acid and bile were treated with heat at $80^{\circ}C$ for 15 min, and at $70^{\circ}C$ for 5 min in Bifidobacterium and yeast. As a result of heat treatment, 38 strains were obtained as heat-tolerant strains. All of heat-tolerant strains were tested for antibiotic resistance against virginiamycin, sulfathiazole, aureomycin, neomycin, linsmycin, tiamulin and ASP250 which were used as feed additives for growth promotion in pigs. Finally, one strain each from Lactobacillus, Streptococcus, Bifidobacterium and yeast that showed resistance to acid, bile, heat and antibiotics was selected for probiotic use in pigs.

• 대한치과보철학회지
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• 제44권4호
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• pp.466-476
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• 2006

Purpose : Colonization of denture soft lining materials by Candida albicans can result in clinical problem, and deterioration of the materials. This study aimed to compare the retention and penetration of C. albicans into four denture soft lining materials commonly used. Materials and methods : Four denture soft lining materials (Coe-comfort$^{(R)}$, Coe-soft$^{(R)}$, GC soft liner$^{(R)}$, and Tissue conditioner$^{(R)}$) discs were prepared to glass slide and dental stone. Adherence of yeast to surfaces was monitored after one hour incubation of standardized washed cell suspension with test disc surfaces. Adherent cells stained with acridine orange were counted fluorescence microscopy. Penetration of yeast into materials bonded with acrylic resin after 1, 2, 3,4, 5, 6 and 7 days incubation was observed through sections stained using acridine orange and estimated to quantitative analysis using radioisotope. Results : There was statistical significance in cell numbers between smooth and rough surfaces(p<0.05). Higher numbers of cells were observed on rough surfaces. There was statistical significance in adherent cell numbers into smooth and rough surfaces individually(p<0.05). According to the increase of incubation periods, the cells penetrated into denture soft lining materials were shown to increase. The differences among all kinds of soft liner were statistically significant(p<0.05),and the largest number of cells penetrated into soft liners was observed in the Coe-soft$^{(R)}$. Conclusion : Initial adherence and penetration of yeast into denture soft lining materials has been influenced by surface roughness and chemical composition of them. The selection of appropriate materials and their fabrication may promote clinical performance.

• Asian-Australasian Journal of Animal Sciences
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• 제30권2호
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• pp.211-220
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• 2017

Objective: The aim of the present study was to investigate the effect of yeast with bacteriocin and Lactobacillus cultures (mixture of Lactobacillus agilis BCRC 10436 and Lactobacillus reuteri BCRC 17476) supplements, alone or in combination, on broiler chicken performance. Methods: A total of 300, 1-d-old healthy broiler chickens were randomly divided into five treatment groups: i) basal diet (control), ii) basal diet+0.25% yeast (Saccharomyces cerevisiae) (YC), iii) basal diet+0.25% yeast with bacteriocin (BA), iv) basal diet+Lactobacillus cultures (LAB), and v) basal diet +0.25% yeast with bacteriocin+Lactobacillus cultures (BA+LAB). Growth performance, cecal microbiota, cecal fermentation products, and blood biochemistry parameters were determined when chickens were 21 and 35 d old. Results: The supplementation of YC, BA, and BA+LAB resulted in a significantly better feed conversion rate (FCR) than that of the control group during 1 to 21 d (p<0.05). The LAB supplementation had a significant effect on the presence of Lactobacillus in the ceca at 35 d. None of the supplements had an effect on relative numbers of L. agilis and L. reuter at 21 d, but the BA supplementation resulted in the decrease of both Lactobacillus strains at 35 d. The BA+LAB supplementation resulted in higher short chain fatty acid (SCFA) in the ceca, but LAB supplementation significantly decreased the SCFA at 35 d (p<0.05). All treatments tended to decrease ammonia concentration in the ceca at 21 d, especially in the LAB treatment group. The BA supplementation alone decreased the triacylglycerol (TG) concentration significantly at 21 d (p<0.05), but the synergistic effect of BA and LAB supplementation was required to reduce the TG concentration at 35 d. The YC supplementation tended to increase the plasma cholesterol at 21 d and 35 d. However, the BA supplementation significantly decreased the cholesterol and low density lipoprotein cholesterol level at 35 d. In conclusion, the BA+LAB supplementation was beneficial to body weight gain and FCR of broiler chickens. Conclusion: The effect of BA and LAB supplementation may be a result of the growth of lactic acid bacteria enhancement and physiological characterization of bacteriocin, and it suggests that the BA and LAB supplementation level or Lactobacillus strain selection should be integrated in future supplementation designs.

• KSBB Journal
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• 제20권4호
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• pp.285-290
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• 2005

Sanguinarine은 천연 항균성 물질로 의약품, 생활용품 그리고 화장품 등 그 이용은 다양하나 가격이 비싸고 수율이 따르지 못하는 점을 식물세포배양을 통하여 해결할 수 있을 것으로 기대된다. Sanguinarine의 생산을 극대화하기 위하여 전통적인 방법인 환경적 요인을 고려한 cell selection방법과 유전적 접근인 protein의 변화를 동시에 관찰하였다. Yeast extract를 elicitor로 이용하였을 경우에 control에서는 관찰 할 수 없었던 sanguinarine에 해당하는 오렌지색의 형광을 볼 수 있었으며, 실제 metabolite의 분석에서도 sanguinarine의 증가를 확인 할 수 있었다. 세포 내부에서는 sanguinarine이 약 8배의 증가를 보였으며 배지에서는 약 5배의 증가를 보였다. Protein 역시 2-D electrophoresis로 확인한 결과 intensity가 $5\%,\;88\%,\;6.4\%$의 증가, 일정, 감소를 보인 spot들이 elicitor 처리 후 세포에서는 $34\%,\;39.4\%\;26.5\%$로 intensity가 증가된 spot들이 더많이 검출되었다. 본 연구에서는 sanguinarine을 yeast extract를 이용해서 생산량을 증가시키고 sanguinarine의 생산과 관련된 protein의 변화에 대해서 알아보고자 하였다. 본 예와 같은 실험 연구방법이 식물이차대사산물 생산성에 관련된 protein군을 규명하는데 초석이 될 수 있을 것으로 기대된다.