• Applied Biological Chemistry
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• v.13 no.1
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• pp.35-42
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• 1970

Five samples of Korean native Maeju(fermented soy-bean mash) loaves which were collected each from Kyunggi, Chungchung, Kangwon, Cholla and Kyungsang-Do were examined for their fermenting microorganisms. The results of taxonomic and ecological studies of fermentation microorganisms in these Maeju loaves were as the fellows. (1) The fungus flora grew only is the outer layer of Maeju loaves. Miscellaneous molds, 3 species of Mucor, 2 species of Pericallium., one species each of Scopulariopsis and Aspergillus, were isolated. None of them seemed exclusively predominant to be able to designate as the ecologically significant. (2) The bacterial flora which consisted of two species, Bacillus subtilis and Bacillus pumilus were distributed uniformly in th a entire Maeju loaves. The inner parts of Maeju loaves were especially inhabited solely by these bacterial flora. Probably the Korean native Maeju fermentation could be characterized by these bacterial flora. A Staphylococcus species was also isolated probably as a casual contaminant. (3) The yeasts, Rhodotorula flava and Torulopsis dattila, were isolated from Maeju loaves though their ecological significance was not clear. (4) The ecological aspects of fermentation microbes in the outer and inner parts of Maeju loaves were apparently different, consequently different fermentation processes might have occurred in these two parts and it brought quite different final outlooks in the final matured Maeju loaves. The outer part, rather rigid and dry, retained the light brown color of boiled soy-bean; whereas the inner part, soft and sticky, showed dark brown color indicating severe chemical changes. (5) The aflatoxin producing mold, Aspergillus oryzae was isolated from one sample among 5 of Maeju loaves. In addition to the low probability of isolability from Maeju loaves samples, since this mold grew only in the outer layer of Maeju loaves with such a low population density, about $10^4/g$, perhaps the aflatoxin problem in Korean native soysauce may not be critical.

• Food Science and Preservation
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• v.21 no.5
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• pp.757-765
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• 2014

Campbell Early grapes were spontaneously fermented with and without sulfiting to investigate the effect of sulfiting on the fermentation characteristics and physicochemical properties of Campbell Early wine. During the fermentation, the increase in the alcohol and the decrease in the soluble solid contents were faster without sulfiting, as was the increase in the yeast viable counts compared to those with sulfiting. However, the final alcohol and soluble solid contents reached similar levels with and without sulfiting. The PCR-RFLP analysis of the yeast in the ITS I-5.8S-ITS II region revealed that the increase in the S. cerevisiae was faster in the initial fermentation stage and reached a slightly higher level in the late stage with sulfiting than without sulfiting. The wine prepared after the fermentation with sulfiting showed higher malic and tartaric acid contents, as well as methanol, acetaldehyde, and n-propanol contents, than the wine prepared without sulfiting. The ethyl acetate content of the wine without sulfiting was 375.5 mg/L, which was 5.3 times higher than that (70.5 mg/L) with sulfiting. In the sensory evaluation, the wine without sulfiting obtained higher scores in flavor and overall preference than that with sulfiting.

• The Korean Journal of Mycology
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• v.41 no.3
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• pp.185-191
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• 2013

Several yeast colonies were isolated from wild flowers collected from East, West and South coast areas of Korea by plating of flower suspensions on the YPD plates containing antibiotics, streptomycin and ampicillin. Polymerase chain reactions (PCR) were performed for the amplification of D1/D2 region of 26S rDNA for those colonies. PCR-amplified nucleotide sequences were compared using BLAST for their identification. As results, 27 yeast strains belonged to 15 species were isolated from wild flowers collected at Donghae, where is located in eastern coast of Korea. Also, 34 strains belonged to 17 species were isolated from wild flowers of Daecheon, where is located in western coast of Korea. In addition, 22 strains belonged to 13 species were isolated from wild flowers collected at Wando, where is located in southern coast of Korea. Among those 45 species isolated from 3 different collection sites, only 4 species including Cryptococcus laurentii, Metschnikowia koreensis, Pseudozyma rugulosa, and Rhodotorula mucilaginosa were found from all 3 different collection sites. And 5 species including Cryptococcus aureus, Cryptococcus flavus, Hanseniaspora uvarum, Pichia guilliermondii, and Rhodosporidium fluviale were overlapped from the at least 2 different collection sites. Other 23 species were found only in a specific collection sites implying that each area has distinctive yeast flora.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.229-235
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• 2016

Korea has a long history of brewing traditional rice wine using a authentic starter culture called nuruk, which contains natural microbial flora. Because rice wine is consumed fresh without filtration, its viable cells contribute to the biological activities of the wine. In numerous studies, microbial strains isolated from rice wine have been screened for their functionalities, which were mainly probiotic properties and antimicrobial activities. Indeed, some lactic acid bacteria (LAB) were confirmed to have strong probiotic activities as well as other health-promoting effects. Moreover, some of the isolated probiotic strains produced functional compounds, such as exopolysaccharides and γ-aminobutyric acid. For antimicrobial activities, some LAB and yeast strains were identified to produce bacteriocins and killer toxins, respectively, with significantly broad spectrum of antimicrobial activity. These functional strains originating from traditional rice wine and their metabolites can be used directly for the production of value-added food products.

• The Korean Journal of Mycology
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• v.42 no.2
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• pp.178-182
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• 2014

Yeasts are common inhabitants of the phyllosphere, but our knowledge of their diversity in various fruits and blossoms are limited. We collected different kinds of blossoms and unripened fruits from Hanbat arboretum, Daejeon, Korea at the year of 2013. Yeasts were isolated by plating of suspensions prepared for collected samples onto YPD medium containing antibiotics. BLAST searches were subsequently performed for the comparison of the partially determined sequences of D1/D2 domain of 26S rDNA. As a result, we isolated 57 yeast strains of 31 species from 29 different kinds of blossoms and 6 kinds of fruits samples. We found huge differences in yeast flora depending on the sample collection season.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.179-184
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• 2010

Escherichia coli O157:H7 is a food-borne pathogen that causes bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). We compared three selective media and evaluated the performance of immunomagnetic separation (IMS) for the detection of low levels of E. coli O157:H7 in ground beef and radish sprouts with different levels of background flora. Bulk food samples (500 g for each trial) were artificially inoculated with nalidixic acid-resistant E. coli O157:H7 at the lowest dose that would generate 20 partial-positive samples of 25 g each. All samples were homogenized in mTSB (225 mL) and incubated overnight at $37^{\circ}C$. IMS was performed using the enriched mTSB samples (1 mL) along with conventional spreads plated onto three different selective media: Sorbitol MacConkey agar (SMAC), Sorbitol MacConkey agar with cefixime and tellulite (CT-SMAC), and Sorbitol MacConkey agar with nalidixic acid (NAL-SMAC) as the gold standard. Two suspicious colonies from each medium were selected and confirmed usinga serological test after transfer to tryptic soy broth with yeast extract (TSAYE). CT-SMAC was better than SMAC for detecting E. coli O157:H7 in all food types. Although there was no statistical difference in the number of positive samples when using IMS vs. non-IMS techniques, more positive samples were detected when IMS was used in both ground beef and radish sprouts. It appears that the improvement was more significant in radish sprouts, which had a higher level of background flora than ground beef. The results also suggest that the combination of CT-SMAC and IMS is sufficient to recover low levels of E. coli O157:H7 in high background flora food samples.

• Food Science and Preservation
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• v.20 no.6
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• pp.886-893
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• 2013

Several indigenous sulfite-resistant yeasts were isolated at the microbial succession stage of yeast flora during spontaneous fermentation of Campbell Early grapes using a YPD plate that contained 200 mg/L or 500 mg/L potassium metabisulfite. When they were applied to the wine fermentation using the Campbell Early grape and apple juices, strains S13 and D8 showed strong alcohol fermentation and good flavor production. They were identified as Saccharomyces cerevisiae in the phylogenetic analysis based on their ITS 1-5.8S-ITS II DNA sequences. The two yeast strains grew to a high cell density in the YPD media supplemented with 40%(w/v) glucose. They also grew rapidly in the YPD media at $40^{\circ}C$. While strain S13 showed some differences in cell density at the two temperatures, no marked difference was observed during the culture of strain D8. The strains grew relatively well at pH 5.0 and 9.0 compared with pH 7.0, which was the optimum pH for their growth. Especially, strain S13 cultivated in the YPD media at pH 9.0 grew to 93% of the growth of strain D8, which was obtained at pH 7.0.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.253-259
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• 1996

To investigate the yeast florae in the traditional and commercial Kochujang, computer identification systems, Vitek, API kit and conventional identification methods were used. Yeast florae of each process were compared and their typical physiological characteristics were also tested. Various process intervals yielded 330 colonies, which resulted in 11 species 184 strains classified. They were identified into Candida glabrata C. guilliermondii. C. humicola. C. rugosa, C. zeylanoides, Cryptococcus uniguttulatus, Pichia farinosa, Rhodotorula glutinis, Saccharomyces cerevisiae and Zygosaccharomyces rouxii. The strains of Candida, Pichia, Saccharomyces and Zygosaccharomyces were existing in both processes. In case of commercial process, the maximum distribution of Z. rouxii and S. cerevisiae were 33% at 15 day fermentation and 13% at 21 day, respectively. The distribution of Candida spp. was gradually decreased throughtout the fermentation period from 40% to 10%. In the traditional process, the maximum distribution of Z. rouxii and S. cerevisiae were 53% after 3 months and 26% after 7 months, respectively, S. cerevisiae and Z. rouxii showed distintive growth pattern at the high concentration of glucose and sodium chloride and played important roles in both processes of fermentation. Physiological tests revealed that only two major yeasts. S. cerevisiae and Z. rouxii, showed vigorous carbon dioxide formation under the tested conditions.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.40 no.3
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• pp.313-320
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• 2014

In this study, the antimicrobial activity of niaouli leaf extracts was evaluated against skin flora. The skin flora used for experiments were three gram-positive bacteria such as Bacillus subtilis (B. subtilis), Staphylococcus aureus (S. aureus), Propionibacterium acnes (P. acnes), and two gram-negative, Escherichia coli (E. coli), Pseudomonas aeruginosa( P. aeruginosa), and the yeast, Plasmodium ovale (P. ovale). The bioassay applied for determining the antimicrobial effects of niouli leaf extracts or fraction included the disc diffusion assay and broth dilution assay. Minimum inhibitory concentration (MIC) values of 50% ethanol extract on B. subtilis, S. aureus, P. acnes, E. coli and P. aeruginosa were 0.25%, 0.50%, 1.00%, 0.13% and 0.25% respectively and the MIC values of water fraction were 0.25%, 0.25%, 4,00%, 0.25% and 0.25%. P. ovale did not show antimicrobial activities. The MIC values of methyl paraben used as positive control indicated 0.25%, 0.25%, 0.25%, 0.13% and 0.50%. Also, Minimum bactericidal concentration (MBC) values of 50% ethanol extract were 2.00%, 2.00%, 1.00%, 0.50% and 2.00% individually and the MBC values of water fraction were 0.50%, 0.25%, 4.00%, 0.50% and 1.00%. The MBC values of methyl paraben indicated 1.00%, 0.500%, 0.50%, 0.50% and 1.00%. These results showed that water fraction was as good as methyl paraben except for P. acnes. The 50% ethanol extract also showed activity similar with it. Thus, it is concluded that the 50% ethanol extract/fraction of niaouli could be applicable to cosmetics as a natural preservatives effective in antimicrobial activity against skin flora.

• Journal of Dairy Science and Biotechnology
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• v.35 no.1
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• pp.1-7
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• 2017

Made using a natural mixed starter of lactic acid bacteria and yeast, Koumiss is a slightly alcoholic fermented mare's milk beverage, and a traditional drink of the nomadic populations of Central Asia. Cichorium intybus L. (chicory) is a sedative with potential cardioactive properties, and its oligosaccharides are beneficial in maintaining healthy gastrointestinal flora. Hence, in this study, we have generated a functional Koumiss containing two different concentrations of chicory. After fermentation of the Koumiss premix, the TA increased to 0.85~0.88%, and the pH decreased to ~4.3. The addition of either concentration of chicory had no significant effect on pH and TA. However, the taste, flavor, color, texture, and overall acceptability decreased in proportion to the added amount of chicory. This study has provided the first data on Koumiss supplemented with chicory. The results could be useful in developing high-quality Koumiss with functional activity using chicory, and allowing large-scale industrial production. Further studies are needed to determine if chicory root extract is beneficial for lifestyle-related diseases.