Fulvic acid, a humic substance with unique properties, has sparked interest due to its potential applications in the treatment of allergic diseases, Alzheimer's disease, and as a microplastic adsorbent. However, conventional extraction methods produce insufficient quantities for commercial use, which has prompted research to enhance fulvic acid production. In this study, we investigated the impact of Saccharomyces cerevisiae fermentation on the yield and spectral characteristics of fulvic acid extracted from white peat. Fulvic acid was extracted from both S. cerevisiae-treated and untreated white peats using acid precipitation. The yield of fulvic acid from the S. cerevisiae treated group reached its highest at 3.5 % after 72 hr of fermentation, which was significantly higher than the untreated group (1.1 %). Fourier Transform Infrared (FTIR) analysis revealed similarities in functional groups and characteristic absorption bands between the treated and untreated fulvic acid samples. These findings suggest that S. cerevisiae fermentation can increase the yield of fulvic acid extracted from white peat, providing a promising approach for enhancing the commercial viability of fulvic acid production.

Protein can be provided by cultivating various microbes, which contain more than 30% protein content by cell dry weight. This study compared intracellular protein concentrations of various wild-type yeasts from different sources to select the best yeast strain with high protein concentration. Among them, Saccharomyces cerevisiae KCCM 34709, used for molasses fermentation, exhibited 4.1-fold higher protein concentration than a laboratory yeast strain, S. cerevisiae D452-2. In this study, an approach consisting of random mutagenesis coupled with the Bradford protein assay-based screening method was applied to enhance the S. cerevisiae KCCM 34709 protein content. Among 1,000 mutants, the #180 mutant strain produced 5,041±519 mg/L total amino acid in 48 h, which was 31% higher than the parental S. cerevisiae KCCM 34709 strain. These results demonstrate that the #180 mutant strain can be an attractive cell factory for animal-free protein production.

참다래 열매로부터 분리한 균주의 형태학적 특성과 DNA를 분리하여 효모의 동정에 사용되는 특이적 프라이머로 PCR 증폭을 한 후 생성된 PCR 산물의 염기서열 분석 결과, S. cerevisiae로 동정하였고, 동정된 균주는 S. cerevisiae HKFR18로 명명하였다. HKFR18을 적용하여 병행복발효, 단행복발효 및 단발효를 실시한 결과, 병행 복발효 산업에서 사용되는 상업용 효모 S. cerevisiae La parisienne 대비 발효제로 개량누룩 사용 시험구의 경우, 동등 수준의 알코올 생성능을 나타내었고, 신맛의 특성과 강도에 차이를 나타낼 수 있는 유기산 조성의 차이가 확인되 었으며, 입국 사용 시험구의 경우에는 알코올 생성능, 유기산 조성 및 향기성분 조성에서도 특이적인 차이는 관찰 되지 않았다. 단행복발효 산업현장에서 사용되고 있는 상업용 균주인 S. cerevisiae US-05 시험구 대비 HKFR18 시험구에서 동등 수준의 알코올 생성능이 확인되었고, 총 유기산 함량은 동등 수준이지만 조성에서는 차이가 확인 되었으며, 향기성분 조성도 유의적인 차이를 나타내는 성분들이 검출되었다. 단발효 산업현장에서 사용되고 있는 상업용 균주인 S. cerevisiae Fermivin 시험구 대비 HKFR18 시험구에서 동등 수준의 알코올 생성능과 총 유기산 함량은 동등 수준이지만 조성에서는 상대적으로 acetic acid 함량이 낮은 특성, 검출된 향기성분 대부분 높은 함량을 나타내었다. 이와 같이 국내 자생 S. cerevisiae 균주인 S. cerevisiae HKFR18이 주류 산업 현장에서 적용 되고 있는 상업용 S. cerevisiae 균주의 대체 가능한 주류 양조 가능성이 확인되었으므로 HKFR18과 상업적으로 이용되고 있는 S. cerevisiae 균주와의 관능품질 차별화 및 계통군 분류에 대한 심화 연구를 통하여 국내 자생 생물자원의 활용 가능성을 제고할 수 있는 단서를 제공할 수 있 을 것으로 생각된다.

Malodor emitted while producing fertilizer from hatchery egg waste treated with microorganism is an important limiting factor. To reduce this problem, we attempted to use two yeast strains, Saccharomyces cerevisiae, KACC 30008 and KACC 30068. Both yeast strains reduce ammonia gas emission 35.4% than only treated with bacterium, Bacillus amyloliquefaciens. When both strains were used together, that was reduced as 57.1%. KACC 30008 and 30068 strains reduced hydrogen sulfide 42 and 90.4%, respectively. Both strains together reduced hydrogen sulfide gas as 98.5%. KACC 30008 did not decrease methyl mercaptan emission. However KACC 30068 decreased 40% and both strains together decreased the gas emission as 66.7%. Overall, this study showed that yeast treatment could enhance the effect of B. amyloliquefaciens treatment in the reduction of malodorous gas emission.

The bioconversion of cellulosic biomass hydrolyzates consisting mainly of glucose and xylose requires the use of engineered Saccharomyces cerevisiae expressing a heterologous xylose pathway. However, there is concern that a fungal xylose pathway consisting of NADPH-specific xylose reductase (XR) and NAD+-specific xylitol dehydrogenase (XDH) may result in a cellular redox imbalance. However, the glycerol biosynthesis and glycerol degradation pathways of S. cerevisiae, termed here as the glycerol cycle, has the potential to balance the cofactor requirements for xylose metabolism, as it produces NADPH by consuming NADH at the expense of one mole of ATP. Therefore, this study tested if the glycerol cycle could improve the xylose metabolism of engineered S. cerevisiae by cofactor balancing, as predicted by an in-silico analysis using elementary flux mode (EFM). When the GPD1 gene, the first step of the glycerol cycle, was overexpressed in the XR/XDH-expressing S. cerevisiae, the glycerol production significantly increased, while the xylitol and ethanol yields became negligible. The reduced xylitol yield suggests that enough NAD+ was supplied for XDH by the glycerol cycle. However, the GPD1 overexpression completely shifted the carbon flux from ethanol to glycerol. Thus, moderate expression of GPD1 may be necessary to achieve improved ethanol production through the cofactor balancing.

The aim of this study was to evaluate immunopotentiating activities of β-glucan derived from Saccharomyces (S.) cerevisiae and to select new strains having possibility as an immune-enhancing substance. We examined SB20 strains derived from commercial product as a control, and extracted β-glucans from the four strains of S. cerevisiae. RAW264.7 macrophages were treated with heat-killed yeasts, β-glucans, and lipopolysaccharide (LPS). The production of nitric oxide (NO) and cytokines such as TNF-α and IL-1β were then quantified. When macrophages were induced directly by in vitro addition of β-glucan, little production of NO and IL-1β was observed. When pretreated with strong stimulants, i.e., LPS, most yeasts showed down-modulation of NO and IL-1β production. However, TNF-α secretion was triggered by β-glucans and even more increased by the mixture effect of LPS and β-glucans. In particular, S6 strain induced TNF-α secretion more than other strains. Therefore, we can conclude that the S6 strain has possibility as an immune-enhancing substance.

Mitochondria diseases have been reported to involve structural and functional defects of complex I-V. Especially, many of these diseases are known to be related to dysfunction of mitochondrial proton-translocating NADH-ubiquinone oxidoreductase (complex I). The dysfunction of mitochondria complex I is associated with neurodegenerative disorders, such as Parkinson's disease, Huntington's disease, and Leber’s hereditary optic neuropathy (LHON). Mammalian mitochondrial proton-translocating NADH-quinone oxidoreductase (complex I) is largest and consists of at least 46 different subunits. In contrast, the NDI1 gene of Saccharomyces cerevisiae is a single subunit rotenone-insensitive NADH-quinone oxidoreductase that is located on the matrix side of the inner mitochondrial membrane. The Saccharomyces cerevisiae NDI1 gene using a recombinant adeno-associated virus vector (rAAV-NDI1) was successfully expressed in AML12 mouse liver hepatocytes and the NDI1-transduced cells were able to grow in media containing rotenone. In contrast, control cells that did not receive the NDI1 gene failed to survive. The expressed Ndi1 enzyme was recognized to be localized in mitochondria by confocal immunofluorescence microscopic analyses and immunoblotting. Using digitonin-permeabilized cells, it was shown that the NADH oxidase activity of the NDI1-transduced cells was not affected by rotenone which is inhibitor of complex I, but was inhibited by antimycin A. Furthermore, these results indicate that Ndi1 can be functionally expressed in the AML12 mouse liver hepatocytes. It is conceivable that the NDI1 gene is powerful tool for gene therapy of mitochondrial diseases caused by complex I deficiency. In the future, we will attempt to functionally express the NDI1 gene in mouse embryonic stem (mES) cell.

NAC는 GSH의 전구물질로, thiol기를 포함하는 항산화제 중 하나로 잘 알려져 있으며, 방사선 조사 시 발생하는 생체 내 영향을 감소시켜 생체 손상의 방호 및 회복에 도움을 주는 방사선 방어제로 이용된다. S. cerevisiae에서 항산화제 NAC를 전처리 함에 따라 이온화 방사선 조사에 따른 효모의 세포사멸 방어효과 및 superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx)와 같은

Cisplatin(ctr-diamminedichlorop1atium) is one of the most effective anti-cancer drugs being clinically used in the treatment of solid tumors. Despite its therapeutic benefits, its use in clinical practice is often limited because of dose related toxicity. It is known that yeast cell wall beta-glucans possess immuno-modulating properties, which allows for their application in antitumor therapy. 1S2 is a kind of beta-glucan derived from the cell wall of mutated Sacchammyces cerevisiae, which exhibits anti-cancer activity in vitro and in vivo. The present study explored the possibility of combination therapy of IS2 with cisplatin. In experimental metastasis of colon26M3.1 cells, prophylactic intravenous administration of IS-2 in combination with cisplatin effectively inhibited tumor metastasis compared with cisplatin alone or IS-2 treatment in vivo. IS-2 effectively enhanced Thl type cytokines including IFN-r, IL-2, ILf2 and GM-CSF. Simultaneously, this combined treatment inhibited production of Th2 type cytokines compared with control. These results suggested that IS-2 can be applied in combination therapy with anti-cancer drugs to minimize their side effects.

Many studies propose that dysfunction of mitochondrial proton-translocating NADH-ubiquinone oxidoreductase (complex I) is associated with neurodegenerative disorders, such as Parkinson's disease and Huntington's disease. Mammalian mitochondrial proton-translocating NADH-quinone oxidoreductase (complex I) consists of at least 46 different subunits. In contrast, the NDI1 gene of Saccharomyces cerevisiae is a single subunit rotenone-insensitive NADH-quinone oxidoreductase that is located on the matrix side of the inner mitochondrial membrane. With a recombinant adeno-associated virus vector carrying the NDI1 gene (rAAV-NDI1) as the gene delivery method, we were able to attain high transduction efficiencies even in the human epithelial cervical cancer cells that are difficult to transfect by lipofection or calcium phosphate precipitation methods. Using a rAAV-NDI1, we demonstrated that the Ndi1 enzyme is successfully expressed in HeLa cells. The expressed Ndi1 enzyme was recognized to be localized in mitochondria by confocal immunofluorescence microscopic analyses and immunoblotting. Using digitonin-permeabilized cells, it was shown that the NADH oxidase activity of the NDI1-transduced HeLa cells were not affected by rotenone which is inhibitor of complex I, but was inhibited by flavone and antimycin A. The NDI1-transduced cells were able to grow in media containing rotenone. In contrast, control cells that did not receive the NDI1 gene failed to survive. In particular, in the NDI1-transduced cells, the yeast enzyme becomes integrated into the human respiratory chain. It is concluded that the NDI1 gene provides a potentially useful tool for gene therapy of mitochondrial diseases caused by complex I deficiency.