• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.445-451
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• 1996

The strain YCH-37, which produces yeast cell wall lytlc enzyme, was isolated from soil. From the microscopic observation, morphological and cultural characteristics, this strain was identified to fungus, Dicyma sp. So, we named this strain as Dicyma sp. YCH-37. The lytic enzyme effectively lysed Salmonella typhimurium among intact living bacteria and Torulopsis, Hansenula, Zygosaccharomyces among intact living yeast, as well as autoclaved yeast strains. The yeast cell wall lytic enzyme was succesively purified to 204 folds with 13% yields through yeast glucan affinity adsorption and DEAE-cellulose column chromatography. The enzyme was identified to monomeric protein with molecular weight of 25,000 daltons from the results of SDS-PAGE and gel filtration. The optimum pH and temperature for the yeast lytic activity were 8.0 and 50$\circ$C, respectively. The enzyme was stable up to 40$\circ$C, and between pH 4.0-pH 10.0.

• Food Science and Preservation
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• v.8 no.3
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• pp.326-330
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• 2001

The characteristics of used wine yeast strains were as follows, S6U showed low fermentation speed than those of other yeast strains, but this strain fermented completely later. The wine fermented by W-3 was very low contents of total acid, 0.75% and the ones fermented by UCD530 and AC- contained much extract, 3.26 mg/L and 3.22 mg/L respectively. The wine fermented by CEG and CS2 were predominant in yellowness, and EC1118 produced large amount of acetaldehyde, 49.9 mg/L than those of other strains. EC1118 and CY3079 displayed low methylene blue dyeing ratio, below 15%, meaning high alcohol tolerance yeast. UCD530 produced extremely high contents of glycerol, succinate and lactate compared with other strains. These properties revealed that UCD530 was a typical Saccharomyces bayanus species. The main organic acids produced by wine yeasts were pyruvate, lactate, succinate and acetate. The concentration of acetate in experimental wine could be divided into two parts, one group had concentration below 170 mg/L (UCD530, EC1118, AC-, CY3079, W-3), and the other had concentration up to 350 mg/L (S6U, CEG, CS2).

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.159-163
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• 1983

Film-formation, which often occurs during storage of apple wine, owing to contamination by film-forming yeasts, results in inferior products. Therefore, for the purpose of preventing this occurrence, we isolated and identified yeast strain. Among the total number of 45 yeast strains which were isolated from contaminated apple wine in winery, the strains FY-4 and FY-5 were found to be useful. The strain FY-5, which greatly formed film on apple wine, was identified as Hansenula beijerinckii or similar strain according to taxonomic characteristics.

• Microbiology and Biotechnology Letters
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• v.24 no.6
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• pp.647-651
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• 1996

The development of an enrichment method for the rapid and effective identification of Salmonella spp. in sewage or food was studied. As a growth factor for Salmonella, 10 mM cyclic adenosine monophosphate (cAMP) in trypticase soy broth with 0.6% yeast extract (TSBYE) increased cell number five-folds and 0.6% yeast extract in selenite broth increased cell number ten-folds of control. Bile salts in selenite broth was tested for the selection of S. enteritidis in a mixture with Staphylococcus aureus, Pseudomonas aeruginosa, Lactobacillus plantarum and Escherichia coli. The latter four strains were effectively inhibited at 0.1% bile salt. A two-step culture method was used to enrich Salmonella spp.; a primary-enrichment and secondary- enrichment culture. At a primary-enrichment step, selenite broth with 0.6% yeast extract and 10 mM cAMP was used, and at a secondary-enrichment step, 0.1% bile salt was additionally used. Culture times of a primary- enrichment and a secondary-enrichment step were 8 hr and 6 hr, respectively. In this procedure, cell number increased from 10$^{0.3}$ to 10$^{8.5}$ with inhibition of other strains within 14 hr. In the case of an initial cell concentrarion as low as 10$^{-2}$ cfu/ml, a cell number increased to 10$^{7}$ cfu/ml by using a 10 hr primary-enrichment and 6 hr secondary-enrichment procedure.

• Nutrition Research and Practice
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• v.1 no.4
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• pp.260-265
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• 2007

Preservation methods on the physiological and brewing technical characters in bottom and top brewing yeast strains were investigated. The preserved yeasts were reactivated after 24 months storage and grown up to stationary phase. The samples of filter paper storage indicated a higher cell growth and viability during propagation than those of nitrogen and lyophilization storage independent on propagation temperature. In addition, the filter paper storage demonstrated a faster absorption of free amino nitrogen and a highest level of higher aliphatic alcohols production during propagation than other preservation methods, which can be attributed to intensive cell growth during propagation. Moreover, the filter paper storage showed a faster accumulation for glycogen and trehalose during propagation, whereas, in particular, lyophilization storage noted a longer adaptation time regarding synthesis of glycogen and trehalose with delayed cell growth. In beer analysis, the filter paper storage formed an increased higher aliphatic alcohols than control. In conclusion, the preservation of filter paper affected positively on yeast growth, viability and beer quality independent on propagation temperature. In addition, in this study, it was obtained that the HICF and Helm-test can be involved as rapid methods for determination of flocculation capacity.

• Mycobiology
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• v.46 no.1
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• pp.33-46
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• 2018

Gray mold (Botrytis cinerea) is one of the most common diseases of strawberries (Fragaria${\times}$ananassa Duchesne) worldwide. Although many chemical fungicides are used for controlling the growth of B. cinerea, the risk of the fungus developing chemical resistance together with consumer demand for reducing the use of chemical fungicides have necessitated an alternative method to control this pathogen. Various naturally occurring microbes aggressively attack plant pathogens and benefit plants by suppressing diseases; these microbes are referred to as biocontrol agents. However, screening of potent biocontrol agents is essential for their further development and commercialization. In this study, 24 strains of yeast with antagonistic ability against gray mold were isolated, and the antifungal activity of the volatile and diffusible metabolites was evaluated. Putative mechanisms of action associated with the biocontrol capacity of yeast strains against B. cinerea were studied through in vitro and in vivo assays. The volatile organic compounds produced by the Galactomyces candidum JYC1146 could be useful in the biological control of plant pathogens and therefore are potential alternative fungicides with low environmental impact.

• Journal of the Korean Applied Science and Technology
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• v.34 no.1
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• pp.33-40
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• 2017

To isolate and identify the yeast strains associated with D. morbifera, homogenized D. morbifera root samples were spread onto GPY, DG18, SCG and DOB agar media containing antibiotics, Triton X-100, and l-sorbose. Total 81 yeast isolates were analyzed by sequencing of internal transcribed spacer (ITS) region of the ribosomal DNA. The results showed that the root-associated yeast species were composed of the genera Vanderwaltozyma (40 isolates), Cryptococcus (40 isolates), and Kluyveromyces (one isolate). Moreover, the Kluyveromyces isolate exhibited high bioethanol productivity. In addition, the Vanderwaltozyma and Cryptococcus were dominant in D. morbifera roots. The specific yeast community associated with D. morbifera roots was identified by phylogenetic sequence analyses. These yeast isolates may have industrial applications as biosurfactant and bioethanol.

• Journal of the korean veterinary medical association
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• v.18 no.3
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• pp.30-34
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• 1982

The present study was conducted in order to investigate Candida sp. associated with bovine mastitis epidemiologically in the Jinju district. A total of 42 strains of yeast-like fungi isolated from 166 quarter milk were identified as 26 strains of Candida

• Korean Journal of Environmental Agriculture
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• v.32 no.3
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• pp.240-243
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• 2013

BACKGROUND: Several yeast species have potential applications in biotechnology and the identification of such yeast species is of great interest. The first step in the identification of yeasts is the establishment of an effective isolation method. Thus, we compared the efficacy of different yeast media in the isolation of yeast associated with Aloe vera and Aloe saponaria. METHODS AND RESULTS: In this study, we spread homogenized A. vera and A. saponaria leaves onto 4 different yeast selective media containing chloramphenicol, streptomycin, Triton X-100 and L-sorbose. We observed high selectivity for yeast and many colonies on media. We isolated 67 yeast strains from A. vera and 42 yeast strains from A. saponaria. We used phylogenetic analysis to identify the yeast isolates based on ITS region sequencing and performed sequence analysis on representative isolates from each agar plate. Further, we compared the sequences obtained with reference sequences. The yeast species isolated from A. vera were as follows: 56 isolates of Meyerozyma, 9 isolates of Cryptococcus, and 1 isolate each of Rhodotorula and Sporobolomyces. Those isolated from A. saponaria were as follows: 41 isolates of Rhodosporidium and 1 isolate of Sporobolomyces. CONCLUSION(S): All the isolates obtained using large agar plate containing chloramphenicol, streptomycin, Triton X-100 and L-sorbose were identified as yeast. Therefore, we concluded that this method is useful for selective screening of yeast species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1065-1070
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• 1998

Lactic acid bacteria KL 1, KD 6, KL 4 strains isolated from kimchi, or obtained Lactobacillus acidophilus, Lactobacillus plantarum, Leuconostoc mesenteroides with and without yeast(Saccharomyces cerevisiae) were inoculated in fruit vegetable juice for mixed culture fermentation 3 days at 3$0^{\circ}C$, and then their chemical changes were studied during fermentation. The amount of organic acid produced by the mixed culture fermentation of KL 1 and yeast was 0.82%(3 days) or 0.58%(1 day) and with the final pH of 3.3(3 days) or 4.2(1 day). These mixed culture systems of isolated strains or other bacterial strains had almost similar results of growth rate and acid production. The contents of vitamin C and carotene were retained and stabilized as 70~80% level of their initial values after 24 hrs fermentation. And also ethanol was produced as of the range in 9.6mg%(W/V) by the mixed culture fermentation of KL 1 and yeast, however, the content of ethanol in single culture fermentation by KL 1 strain was much lower than that of mixed culture. The major components of organic acids in fermented juice by mixed culture were considered as malic(26.0%), lactic(49.9%), succinic and citric acid, whereas these of unfermented juice were malic(53.2%), citric and other acids. On other hand, reducing sugar was decreased from 18.3mg/ml in fresh juice to about 12mg/ml in juice by mixed culture fermentation. Concentrations of fructose, glucose and sucrose were also greatly reduced in fermented juice.