• 한국동물학회:학술대회논문집
• /
• 한국동물학회 1995년도 한국생물과학협회 학술발표대회
• /
• pp.82-82
• /
• 1995

Regulation of enzyme synthesis by transcriptional and translational control systems provides rather stable adaptation to change of amino acid level in the growth medium, while manipulation of enzyme activity through endproduct feedback inhibition represents rather short-term and reversible ways of adjusting metabolic fluctuation of amino acid level. Various control mechanisms interplay to regulate genes encoding enzymes for amino acid biosynthesis in the yeast, Sacchromyces cerevisiae. When amino acids are in short supply, genes under a cross-pathway regulatory mechanism Or general amino acid control (general control) increase their action, in which Gcn4p is the major positive regulator of gene expression. When cells are cultured in minimal medium, basal level expression is also regulated by supplementary control elements, where inorganic phosphate level is additionally involved. Most of amino acid biosynthetic genes are also regulated by the level of endproduct of the pathway. This pathway-specific regulatory mechanism is called specific amino acid control (specific controD, under which gene expression is reduced when endproduct is present in the medium. Derepression of a gene through general control can be usually overridden by repression through specific control, where the endproduct level of that particular pathway is high and not limiting. In this presentation, regulatory factors for basal level expression and general control of yeast amino acid biosynthesis will be discussed, m addition to pathway-specific repression patterns and interaction between CrOSS- and specific-control mechanisms. Preliminary results are also presented from the investigation of the cloned genes in the threonine biosynthetic pathway of the yeast. yeast.

• 한국어업기술학회:학술대회논문집
• /
• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
• /
• pp.249-250
• /
• 2000

양식산업의 성공에 있어 저렴하고 높은 영양가를 가진 사료가 차지하는 비중은 너무나도 중요하다, 유용 어패류의 종묘생산을 위한 초기먹이생물로서 그간 단세포 조류가 주로 사용되어 왔는데(Benemann, 1992), 단세포 조류는 대량배양을 위한 노동력 및 세포수거시 비용이 많이 드는 단점을 가지고 있다. 이러한 단점을 보완하는 algae 대체품으로 yeast가 고려되고 있다. Yeast 단백질 사료로서 Sacchromyces cerevisae, candida utilis와 같은 yeast가 관심을 끌고 있는데, 이들을 건조중량 가운데 50%이상의 단백질을 함유하고 있다(Ziino et al., 1998). (중략)

• KSBB Journal
• /
• 제7권1호
• /
• pp.9-14
• /
• 1992

A cone type of tower fermentor loaded with flocculating Sacchromyces uvarum was used to study the fermentor performance. The performance of cone type fermentor was compared with those of other fermentors. The maximum yeast concentration in the cone type of tower fermentor was 35.9-43.0g/1.hr and the maximum ethanol productivity was 14.75g/1.hr at the dilution rate 0.26 $hr^{-1}$. The ethanol yield was 0.446-0.472g ETOH/g Glucose. It was concluded that a cone type of tower fermentor might offer better perspectives for continous etanol fermentation.

• 미생물학회지
• /
• 제26권1호
• /
• pp.67-71
• /
• 1988

It has been observed that white loght can suppress both cell growth and protein secretion in Baker's yeast. This effect was explored in batch liquid fermentations. Possible applications of this phenomenon are (a) use as a tool for pre-concentrating excreted enzymes prior to subsequent purification and (b) an engineering variable for regulation yeast fermentations.

• KSBB Journal
• /
• 제9권2호
• /
• pp.104-107
• /
• 1994

Cone 형태 탑형발효기에서 연속발효실험을 수행 결과 발효조 최대 효모 농도는 37.5-39.5g/l이었고 최대 에탄올 생산성은 희석율 0.32 $hr^{-1}$에서 16.3gEtOH/L.hr 이었다. 평균 에탄올 수율은 0.48 g/EtOH/g glucose로서 이는 이론적 수율의 94%였다. Cone형태 탑형발효기는 에탄올 연속생신시 효과적인 발효기로 생각되었다.

• 한국식품영양과학회지
• /
• 제39권12호
• /
• pp.1860-1866
• /
• 2010

오미자로부터 야생효모 Saccharomyces cerevisiae(S. cerevisiae) SH8094와 S. cerevisiae SH2855를 분리, 동정하였으며, 이 효모를 이용하여 오미자 발효주를 제조하였다. 야생효모 S. cerevisiae SH8094와 S. cerevisiae SH2855를 이용한 오미자 발효주와 시판효모 Lalvin 1118을 이용한 오미자 발효주의 이화학 특징과 관능 특성을 비교 분석하였다. 그 결과, 야생효모 S. cerevisiae SH8094로 제조한 오미자 발효주가 pH 2.8, 산도 1.1%, 당도 14.5oBrix, 알코올 함량 9%를 나타냈으며, 목넘김, 종합적 기호도에 있어서 높은 점수를 얻었다. 또한 오미자로부터 분리된 야생효모 S. cerevisiae SH8094와 S. cerevisiae SH2855를 이용하여 만든 오미자 발효주와 상업적으로 판매되는 오미자 발효주의 관능 특성을 비교한 결과, 생오미자에서 분리된 야생효모 S. cerevisiae SH8094로 제조한 오미자 발효주가 상업적으로 판매되는 오미자주보다 향, 색, 종합적 기호도에 있어서 우수하게 나타났다. 이로써 오미자로부터 분리한 효모 S. cerevisiae SH8094를 이용한 우수한 오미자 발효주 제조의 가능성을 확인하였다.

• 한국어병학회지
• /
• 제34권2호
• /
• pp.185-199
• /
• 2021

Vibriosis is an important septicemic bacterial disease that affects a variety of commercial fish species, including cultured Dicentrarchus labrax. Nanotechnology has become an important modern tool for fish diseases prevention. Furthermore, nanomaterials have the ability to prevent and treat fish diseases. The current study was aimed to identify the causative agent of massive mortality of D. labrax commercial farm in Alexandria, Egypt. Experimental infection and the median lethal dose (LD50) of pathogenic isolate were assessed. Also, the effect of ginger nanoparticles (GNPs) and Sacchromyces cerevisiae as feed additives for prevention of vibriosis in D. labrax was carried out. Similarly, the tissue immunstimulant genes, IL-1β and TLR2 were measured in the spleen of feeding groups. The clinical signs of naturally diseased D. labrax showed corneal opacity and paleness of gills with excessive mucous secretion. The post-mortem abnormalities were severe hemorrhage and adhesion of internal organs. After bacteriological isolation and identification, the causative agent of mortality in the current study was Vibrio alginolyticus. The LD₅₀ of V. alginolyticus was 1.5×10^5.4 CFU/ml. The experimentally infected D. labrax showed ulceration, exophthalmia and skin hemorrhages. The post-mortem findings of the experimentally infected D. labrax revealed internal hemorrhage, spleen darkness and paleness of liver. There is no mortality and 100% RPS in groups fed GNPs then injected with V. alginolyticus, in those fed a combination of GNPs and S. cerevisiae and a group fed normal diet then injected with physiological saline (control negative), respectively. Contrarily, there was 10% mortality and 87.5 RPS in the group fed S. cerevisae then injected with V. alginolyticus. On the other hand, the control positive group showed 79% mortality. The spleen IL-1β and TLR2 immunostimulant genes were significantly increased in groups of fish fed GNNP, S. cerevisiae and a combination of GNPs and S. cerevisiae, respectively compared to control group. The highest stimulation of those immunostimulant genes was found in the group fed a combination of GNPs and S. cerevisiae, while fish fed S. cerevisiae had the lowest level. Dietary combination of GNPs and S. cerevisiae was shown to be efficient in preventing of vibriosis, with greatest stimulation of spleen IL-1β and TLR2 immunostimulant genes.

• BMB Reports
• /
• 제30권3호
• /
• pp.167-172
• /
• 1997

The yeast Saccharomyces cerevisiae, mutant CH117, shows a drug-hypersensitivity (dhs) to cycloheximide, bleomycin, actinomycin D, 5-fluorouracil. nystatin, nigericin and several other antibiotics. CH 117 was also temperature-sensitive (ts). being unable to grow at $37^{\circ}C$ and secreted more invertase and acid phosphatase into the medium than the parent yeast. CH117 grows very slowly and the cell shape is somewhat larger and more sensitive to zymolyase than the wild type cells. Light microscopic and electron microscopic observation also revealed abnormality of the mutant cell wall. These characteristics indicate that CH117 has a defect in an essential component of the cell surface and that the cell wall which performs barrier functions has become leaky in the mutant. We screened a genomic library of wild type yeast for clones that can complement the mutation of CH117. A plasmid, pCHX1, with an insert of 3.6 kilobases (kbs) could complement the dhs and ts of CH117. Deletion and subcloning of the 3.6 kb insert showed that a gene for the complementation of mutant phenotypes was located in 1.9 kbs Puvll-Hindlll fragment.

• Mycobiology
• /
• 제38권3호
• /
• pp.206-209
• /
• 2010

To produce bioactive compound enriched yeast using medicinal Gugiga (Lycium chinensis Mill), several edible Saccharomyces species were cultured in Gugija extracts added yeast extract, peptone and dextrose medium (GE - YEPD medium) at $30^{\circ}C$ for 24 hr, and their growth were determined. Growth of Saccharomyces cerevisiae K-7 and Sacchromyces cerevisiae ACTC 7904 were better than those of the other yeasts. Two yeasts were selected and then determined their some physiological functionalities after cultivated the yeasts in the GE - YEPD medium and compared those grown on YEPD medium. Antihypertensive angiotensin I-converting enzyme (ACE) inhibitory activity of S. cerevisiae K-7 grown on GE - YEPD medium was about 20% higher than that grown on YEPD medium. Superoxide dismutase-like activity of S. cerevisiae ACTC 7904 was also about 12% more high. However, the other physiological functionalities were almost same or lower. Optimal addition concentration of Gugija extract was 10%, and maximally growth and ACE inhibitory activity of S. cerevisiae K-7 were shown when the strain was cultured in 10% Gugija extracts containing YEPD medium at $30^{\circ}C$ for 12 hr.

• Journal of Microbiology and Biotechnology
• /
• 제9권1호
• /
• pp.122-125
• /
• 1999

Gcn4p, a transcriptional activator protein of the yeast, Sacchromyces cerevisiae, binds to the specific sequence in the promoters of many amino acid biosynthetic genes for general control. The serine residue (Ser 242) of Gcn4p directly contacts the DNA. Here, for inspecting the DNA binding properties and the level of transcriptional activation of Gcn4p, we introduced a polymerase chain reaction (PCR) site-directed saturation mutation library into the Ser 242 site using 2 outside primers and 2 oligonucleotides with its codons fully degenerated. The sequencing analysis of 146 samples revealed the even nucleotide distribution within the experimental error showing 23, 26, 25, and 26％ frequency of U, C, A, and G bases, respectively. This method turned out to be a simple, fast, and economical method for constructing a library of all 20 amino acids at specific codon.