• Korean Journal of Microbiology
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• v.22 no.4
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• pp.215-222
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• 1984

A fungus producing cell wall lytic enzyme for Rhodotorula glutinis was isolated from local soil and identified partially as a species of Aspergillus fumigatus group. Thd cell wall lytic enzyme was an inducible exoenzyme and composed of at least lytic polysaccharidase and protease which act cooperatively in the lysis of intact cells. The lytic polysaccharidase was not able to hydrolyze ${\beta}-1,\;3\;and\;{\beta}-1$, 6-glucan which have the same types of bond as found in the cell wall of Ascomycetous yeasts. The lytic polysaccharidase alone was sufficient to hydrolyze the fractionated cell wall (alkali-insoluble residues) of R. glutinis, whereas it showed low activity against intact cells.

• Microbiology and Biotechnology Letters
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• v.36 no.2
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• pp.101-105
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• 2008

In order to obtain yeast cells producing a bacteriocin OR-7, the 180 bp polynucleotide corresponding to the OR-7 gene including codons for start and stop was chemically synthesized and cloned into pAUR123, an yeast expression vector. Transformed yeast cells exhibited growth inhibition of Bacillus subtilis, Campylobacter jeuni, Escherichia coli and Pseudomonas aeruginosa. This result indicates that yeast cells producing OR-7 possess bacteriocidal properties against both Gram positive B. subtilis and Gram negative C. jejuni, E. coli and P. aeruginosa cells. The recombinant yeast strain constructed in this study can be applied in the food preservative or animal feed.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.867-872
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• 2002

This study was performed to investigate the optimum process conditions for manufacturing yeast extract from waste brewer's yeast using various enzymes. Contents of IMP, GMP, free amino acids, and crude protein of yeast extracts were measured by enzymes treatment. Crude protein contents of yeast extracts subjected to cell wall digestion enzyme treatment were 21.1, 33.6, and 28.0% for the control grouup, glucanase (0.5%, 12 h), and tunicase (1%, 18 h), respectively. Crude protein contents of yeast extracts subjected to protease treatment were 22.0, 30.8, and 29.8% for control group, bromelin (1%, 3 h), and protamex (1%, 3 h), respectively. Crude protein content of yeast extract subjected to glucanase and protamex mixed treatment was 34.4%. The total contents of IMP and GMP of yeast extracts subjected to G+P+A (glucanase+phosphodiesterase+adenyldeminase) and G+Pro+P+A (glucanase+protamex+phosphodiesterase+adenyldeaminase) treatments were 1,066 and 1,047 mg/100 g, respectively. The content of free amino acids of yeast extract was the highest (2,302 mg/100 g) in G+Pro+P+A treatment. Optimum concentration and process condition of enzyme treatment to obtain yeast extract with high IMP, GMP, and free amino acid content were in the order of glucanase (0.5%, 12 h), protamex (1%, 3h), phosphodiesterase (0.1%, 3 h) and adenyldeaminase (1%, 1.5 h) treatments.

• Korean Journal of Poultry Science
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• v.32 no.1
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• pp.49-54
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• 2005

An experiment was conducted to investigate whether dietary yeast (Saccharomyces cerevisiae, SC) and its' structural components, i.e., yeast cell-extract (YE) and yeast cell-wall (CW) could influence growth performance, ileal morphology and serum lipids of male broiler chickens. There were four dietary treatments, each consisting of 6 replicates (10 birds per replicate). Chickens were fed a corn-soybean meal base control diet and diets containing SC ($0.5\%$), YE ($0.25\%$) and CW ($0.25\%$), respectively for 5-wk-experimental period. Dietary SC, YE and CW versus the control diet did not affect growth performance of male broiler chickens. Ileal morphology as to villus height, crypt depth and villus:crypt ratio of birds fed on the control diet was not significant from those fed on diets rich in SC, YE and CW, respectively. Dietary SC significantly lowered (P<0.05) serum total cholesterol by on average $19.7\%$ as compared to the control group. In addition, chickens fed on diets with either YE or CW lowered serum cholesterol by on average 15.3 and $12.5\%$, respectively as compared to the control albeit that the former only reached statistical significance. In conclusion, our study observed the hypocholesterolemic effect of SC in male broiler chickens. Moreover, YE, i.e., an extract of intracellular components of SC contains active molecules that are responsible far lowering serum cholesterol concentrations, but their identification at the molecular level needs to be assessed.

• Current Research on Agriculture and Life Sciences
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• v.29
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• pp.37-42
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• 2011

The plant-homologue of Bax Inhibitor, a gene described to suppress the cell death induced by Bax gene expression in yeast, was isolated from rice (Oryza sativa L.). Nucleic acid sequence and amino acid sequence were 741 bp and 247 bp, respectively. The amino acid sequence of the predicted protein was well conserved in plant (84 % in amino acids) and contained five membrane-spanning segments.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.376-379
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• 2000

The methylotrophic yeast Pichia pastoris is one of the best host for the production of foreign proteins because of the presence of the strong AOX1 promoter induced by methanol. Methanol feeding induces the protein production and provides energy sources for the host cells. However, excess methanol inhibits the growth of host cells, while an insufficient methanol lead to poor growth and protein production. We have used various controled methanol feeding strategies to obtain the maximum proteins.

• Environmental Analysis Health and Toxicology
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• v.21 no.1 s.52
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• pp.21-26
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• 2006

본 연구는 DNA 상해유도기작을 규명하기 위하여 하등 진핵생물인 분열형 효모 Schizosaccharomyces pombe로부터 subtraction hybridization방법을 이용하여 자외선 유도 유전자인 UV150과 UV200을 분리하고 그 유전자 구조와 발현양상을 조사하였다. 분리한 유전자의 발현양상을 Northern hybridization 방법으로 살펴본 결과 자외선 조사 1시간 후부터 발현이 증가되었다. 또한 알킬화제인 Methyl Methanesulfonate (MMS) 처리에 의해서도 발현이 증가되었다. 이 결과 다른 UV-inducible유전자와는 다르게 분리한 UV150유전자는 UV에 UV200유전자는 MMS에 의하여 발현이 증가됨을 알 수 있었다. 유전자의 기능을 알기 위하여 URA4 유전자를 이용하여 null-mutant 세포주를 제조하여 그 특성을 살펴본 결과 분리한 UV150 유전자는 세포의 성장에 필수적인 유전자임을 알 수 있었다.

• KSBB Journal
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• v.8 no.4
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• pp.390-396
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• 1993

Effects of various elictitors were investigated to enhance the production of berberine in plant cell suspension cultures of Thalicrtrum rugosum. Treatments of yeast elicitor, 15 different types of abiotic elicitors, 16 kinds of fungal elicitors from three species of fungi were performed. Cell growth and berberine production were examined and compared for both normal and elicitor treated cultures. No distinguished increases in berberine yield by the addition of elicitors could be attained.

• Korean Journal of Microbiology
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• v.33 no.2
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• pp.81-85
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• 1997

Candida속 효모 27종이 표준 균주를 대상으로 세포내 지방산 조성을 기체 크로마토그래피로 분석하여, 함유 지방산의 종류와 함량비를 근거로 27종이 균주를 3개의 분류군으로 나누었다. 이들 지방산 분석에 의한 분류군을 Candida속의 다른 분류학적 결과들인 coenzyme Q 분자종의 종류, DNA 염기함량 분석, ITS 부위의 제한효소 절단 다형질의 양상, 리보좀 소단위 RNA 유전자의 염기배열 보고와 비교 분석하였다. 그 결과 같은 분류군에 위치하는 균주들 사이의 연관 관계가 거의 일치하였다. 다라서 세포내 지방산 분석은 Candida속 규준들을 유전적 동질성을 갖는 균주들로 분류하는 수단으로 사용될 수 있으며, 유전적으로 매우 다양한 균주들의 집단으로 알려진 Candida속에 관한 분류적 고찰에 일차적으로 사용될 수 있는 유용한 수단임을 알 수 있었다.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.258-264
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• 2011

Glutathione (GSH) has important roles in cellular defense against oxidative stress, 1) direct scavenging of reactive oxygen species (ROS), and 2) coenzyme of ROS scavenging enzyme like glutathione peroxidases (GPx). GSH peroxidase reduces free hydrogen peroxide to water using 2GSH. $N$-acetyl-L-cysteine (NAC), one of the antioxidants, is used as a precursor for intracellular GSH. In this study, relation of GSH, NAC, and GSH peroxidase was investigated through transcriptional expression of $GPX1$ and $GPX2$, which are GSH peroxidase encoding genes, in yeast cells treated with 0 mM to 20 mM of NAC or in combination with 100 Gy gamma-rays. The transcriptional expression of $GPX1$ and $GPX2$ was induced by NAC and 100 Gy gamma-rays. The gene expression of both GSH peroxidases was decreased with increasing concentrations of NAC in irradiated yeast cells. These results suggest that elevation of intracellular GSH by NAC and oxidative stress and ROS generated from gamma-rays induces expression of GSH peroxidase genes, and that NAC can protect the yeast cells against ROS generated from gamma-rays through direct scavenging of ROS and transcriptional activation of GSH peroxidase.