• The Korean Journal of Mycology
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• v.49 no.2
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• pp.243-248
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• 2021

In this study, screening of potent non-pathogenic wild yeast with high anti-dementia butyrylcholinesterase (BChE) inhibitory activity and production condition of a BChE inhibitor were described. Among 36 non-pathogenic wild yeasts, Saccharomyces cerevisiae WJSL 0113 showed the highest BChE inhibitory activity of 85.2%. The specific BChE inhibitor was maximally produced when S. cerevisiae WJSL 0113 was cultured at 30℃ for 48 h in a yeast extract-peptone-dextrose medium.

• Journal of Life Science
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• v.18 no.10
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• pp.1377-1383
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• 2008

A bacterium producing non- or partially digestible dextran was isolated from kimchi broth by enrichment culture technique. The bacterium was identified tentatively as Leuconostoc sp. strain SKY. We established the response surface methodology (Box-Behnken design) to optimize the principle parameters such as culture pH, temperature, and yeast extract concentration for maximizing production of dextran. The ranges of parameters were determined based on prior screening works done at our laboratory and accordingly chosen as 5.5, 6.5, and 7.5 for pH, 25, 30, and $35^{\circ}C$ for temperature, and 1, 5, and 9 g/l yeast extract. Initial concentration of sucrose was 100 g/l. The mineral medium consisted of 3.0 g $KH_2PO_4$, 0.01 g $FeSO_4{\cdot}H_2O$, 0.01 g $MnSO_4{\cdot}4H_2O$, 0.2 g $MgSO_4{\cdot}7H_2O$, 0.01 g NaCl, and 0.05 g $CaCO_3$ per 1 liter deionized water. The optimum values of pH and temperature, and yeast extract concentration were obtained at pH (around 7.0), temperature (27 to $28^{\circ}C$), and yeast extract (6 to 7 g/l). The best dextran yield was 60% (dextran/g sucrose). The best dextran productivity was 0.8 g/h-l.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.415-422
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• 2019

Rhodosporidium toruloides has been known as an in vitro model of fat metabolism. The purpose of this study is to identify the triglyceride inhibitory effects of hot water extracts from beetroot using R. toruloides. The triglyceride content of oleaginous yeast cultured from YPD culture medium were regulated by treatment of beet root hot water and ethanol extract, respectively. In addition, the number of cells in the oleaginous yeast was 10.48, 8.46, 12.40, 12.80 and $8.24{\times}10^3cell/mL$. The treatment of hot water extract of beet root increased total lipid content of oleaginous yeast in dose dependently. Moreover, the triglyceride content of oleaginous yeast was decreased by hot water extract of beet root extract, respectively. The fat droplet in the oleaginous yeast decreased according to the concentration of hot water extracts from beetroot. The ratio of increase in the number of cells in the oleaginous yeast were increased dose-dependently by treatment of hot water extract from beetroot compared with control group. The free fatty acid and total carotenoid contents were increased concentration-dependently by treatment of hot water extracts from beetroot. These study results indicate that hot water extracts from beetroot has a triglyceride inhibitory effects.

• Microbiology and Biotechnology Letters
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• v.29 no.4
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• pp.234-239
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• 2001

In order to maximize the RNA accumulation and biomass production is Saccharomyces cerevisiae MTY62, a high-content RNA yeast strain, batch and fed-batch cultures were performed. Among the feeding modes of fed-batch cultures examined, the intermittent feeding mode R\`(IFB-lV), in which 50 ml of 40% molasses and 20% com steep liquor (CSL) solution was intermittently fed for 5 times, resulted in the cell concentration of 33.8 g- dry cell weight/1 and the RNA concentration of 5221 mg-/l, and RNA content of 153 mg-RNA/g-dry cell weight. The constant fed-batch with feeding mode III (CFB-III), in which the feeding rate of 40% molasses and 20% CSL solution was stepwisely decreased from 48 mph (9-13 h), to 24 mph (13-21 h), and to 18 ml/h (21∼ 48 h), gave the highest cell concentration of 42.7 g-dry ceil weigh71 and R7IA concentration of 5536 mg-RNA/1, which were about 2.4-fold and 1.9-fold increased levels, respectively, compared to the results of batch culture. However, the RNA con- tent of 130 mg-RNA/g-dry cell weight of the fed-batch was lower than that of the batch culture (171 mg-RNA/g-dry cell weight) and other fed-batch cultures. When the specific growth rates in the fed-batch cultures were increased, the RNA contents increased. This result indicates that the RNA content is adversely proportional to the cell concen- tration. However, at the same specific growth rate, the RNA content was maintained at higher level in the intermit- tent fed-batch than in the constant fed-batch culture.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.352-357
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• 2006

In this study, the growth characteristics of Lactobacillus helveticus ATCC 55163 were evaluated. The species was cultured in three different types of broths which included the MRS broth, 6%, 12% whey broth, and 6%, 12% whey broth containing 1% yeast extract, respectively. Exponential phase of Lactobacillus helveticus ATCC 55163 was within the range of 3 to 24 hours in the MRS broth and whey broth. The pH value of the whey broth dramatically decreased within the range of 3 to 24 hours. On the contrary, the total titratible acidity(TTA) of whey broth dramatically increased within the same range. During the same time, the lowest pH was showed in the 12% whey broth containing 1% yeast extract, and the highest TTA was showed in the same whey broth. Therefore, the concentration of whey broth and the yeast extract affected the multiplication of the Lactobacillus helveticus ATCC 55163 seriously through the research.

• The Korean Journal of Mycology
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• v.45 no.4
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• pp.336-344
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• 2017

The anti-inflammatory effects of cell-free extracts from wild yeasts, Meyerozyma guilliermondii YJ34-2 and Rhodotorula graminis YJ36-1, caused by the inhibition of nitric oxide (NO) activity and cytotoxic effects were determined. Cell-free extracts from these two yeast strains had dose-dependent inhibitory effects on the production of lipopolysaccharide-induced NO and there were no cytotoxic effects on the treated cells or negative effects on their proliferation. Their cell-free extracts were also shown to have inhibitory effects on pro-inflammatory cytokines, such as tumor necrosis factor $(TNF)-{\alpha}$ and $prostaglandin-E_2$, in a dose-dependent manner. Maximal inhibitory activity on NO production occurred in cell-free extracts of Meyerozyma guilliermondii YJ34-2 cultivated at $30^{\circ}C$ for 24 hr and Rhodotorula graminis YJ36-1 cultivated at $25^{\circ}C$ for 24 hr in the yeast extract-peptone-dextrose (YPD) media.

• Culinary science and hospitality research
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• v.20 no.2
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• pp.100-119
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• 2014

In this study, rice was used with naturally fermented extract to compare and analyze the physico-chemical characteristics and investigated how to make pan bread made with domestic wheat flour added with naturally fermented rice extract. Also, it examined quality characteristics of pan breads prepared with 0, 10, 30, 50, 70% naturally fermented rice starters. As the fermentation time of rice starters increased, pH of bread doughs decreased. On farinograph, water absorption, development time and stability of rice starters samples were lower than the control. RVA(Rapid Visco Analyzer) analysis showed that wheat flour retrogradation was retarded by increasing rice starters content. The weights of pan breads containing rice starters were higher than that of control. The moisture content of pan breads containing rice starters decreased as storage time increased. In analyzing of visible mold colony during 7 days of storage at $28^{\circ}C$, pan breads containing rice starters was retarded mold growth. In the texture analyzer measurement, hardness of breads containing rice starters significantly increased as storage time increased, which was higher than that of control. The result of sensory properties was no significant difference between the group containing 50% naturally fermented rice starters and control group, such as appearance, flavor, taste and overall quality.

• Microbiology and Biotechnology Letters
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• v.3 no.3
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• pp.123-134
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• 1975

Out of 96 yeast strains isolated from various natural habitats, five strains were screened based on their ability to ferment agricultural biproducts such as rice-, barley-and wheat-bran, and sawdust. These were identified as Hansenula anomala var anomala, Candide utilis, C. pelliculosa, Debaryomyces hansenii, and Irpex lacteus. Using these yeasts the above mentioned agricultural biproducts were fermented in various combinations. The fermented product was fed to 180 male Starcroses for eight weeks and obtained a body weight increase of 15.1g a day, while the unfermented control feed increased 10.5g a day.

• The Korean Journal of Mycology
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• v.42 no.3
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• pp.201-206
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• 2014

Sixty one yeast strains of 21 species were isolated from wild flowers in Gogunsanyeoldo, including Seonyudo of Jeollabuk-do, Korea, and identified by comparison of nucleotide sequences for PCR-amplified D1/D2 region of 26S rDNA using BLAST. Among them, Cryptococcus sp. including C. aureus SY1-4 were found to be dominant, and Metschnikowia sp. including M. reukaufii SY20-1 and Rhodotnula sp. such as R. ingeniosa SY1-1 were also abundantly isolated. Some physiological functionalities of the culture broth and cell-free extracts from 61 yeast strains were determined. Supernatant from Metschnilowia reukaufii SY44-6 showed anti-gout xanthine oxidase inhibitory activity of 49.6% and whitening tyrosinase inhibitory activity of 38.4%, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.6
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• pp.829-832
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• 2003

To develop natural food preservatives, ethanol and water extracts were prepared from the cornus (Cornus of officianalis) and antimicrobial activities were examined against 10 microoganisms which were food borne pathogens and/or food poisoning microoganisms, food-related bacteria and yeasts. Ethanol extract exhibited antimicrobial activity for the microoganisms tested, except lactic acid bacteria and yeast. Especially, minimum inhibitory concentrations (MIC) of the ethanol extracts were determined as 0.25 mg/mL against bacteria and 2 mg/mL against target lactic bacteria and yeasts. Antimicrobial activity of the ethanol extracts were not destroyed by the heating at 121$^{\circ}C$ for 15 min and not affected by pH. The ethanol extract of cornus exhibiting high antimicrobial activities were fractionated in the other of diethylether and butanol fractions to test antimicrobial activity The antimicrobial activity adjust bacteria test was highest in the ethanol fraction.