• Culinary science and hospitality research
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• v.8 no.3
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• pp.309-321
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• 2002

In this study, the characteristics of Jeung-pyun hatter were investigated by wine yeast. The processing conditions were optimized by physicochemical characterization including pH, volume, reduced sugar. The effect of yeast concentration, moisture content on the fermentation time and temperature were investigated in view of improving productivity. It was found that the volume was increased at maximum state when the fermentation was carried out at 35 $^{\circ}C$ with 0.1% yeast concentration 60% of moisture. The quality of Jeung-Pyun was most preferable in the condition of 0.1% wine yeast(Pasteur Red) for 8 hrs at 35$^{\circ}C$.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.818-826
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• 2013

To reduce the production cost of Lactobacillus, discarded red ginseng starch was collected from a factory of red ginseng extract in order to develop the Lactobacillus culture medium. According to the analysis of the gensenoside composition of red ginseng starch, the total gensenoside content of starch was 2.73 mg/g, and the gensenoside $Rb_1$, $Rb_2$ and $Rg_3$ contents were 0.1, 0.29 and 0.52 mg/g, respectively. For the preparation of the liquid media, red ginseng starch was added at rates of 0, 5, 10 and 20%. Further, Lactobacillus plantarum 15357 and Leuconostoc mesenteroides sub sp. strains were then inoculated to these prepared broths. With the red ginseng starch medium, the growth rates ($1.42{\times}10^7$ and $2.96{\times}10^{10}$ CFU/mL) and the final cell concentrations were higher than the MM medium ($1.0{\times}10^7$ CFU/mL). The optimal concentration of red ginseng starch and yeast extract as a medium were 20% and 10 g/L, respectively. Under these conditions, the cell mass of L. plantarum 15357 and L. mesenteroides sub sp. reached $5.11{\times}10^{10}$ and $8.17{\times}10^{10}$ CFU/mL. These results show a great possibility for the utilization of red ginseng starch as economic medium sources in the production of cell mass of lactic acid bacteria. This is the first trial of development of economic LAB growth medium using discarded red ginseng starch.

• Mycobiology
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• v.48 no.3
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• pp.195-203
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• 2020

Marine yeasts have tremendous potential in industrial applications but have received less attention than terrestrial yeasts and marine filamentous fungi. In this study, we have screened marine yeasts for amylolytic activity and identified an amylase-producing strain PH-Gra1 isolated from sea algae. PH-Gra1 formed as a coral-red colony on yeast-peptone-dextrose (YPD) agar; the maximum radial growth was observed at 22 ℃, pH 6.5 without addition of NaCl to the media. Based on the morphology and phylogenetic analyses derived from sequences of internal transcribed spacer (ITS) and a D1/D2 domain of large subunit of ribosomal DNA, PH-Gra1 was designated Sporidiobolus pararoseus. S. pararoseus is frequently isolated from marine environments and known to produce lipids, carotenoids, and several enzymes. However, its amylolytic activity, particularly the optimum conditions for enzyme activity and stability, has not been previously characterized in detail. The extracellular crude enzyme of PH-Gra1 displayed its maximum amylolytic activity at 55 ℃, pH 6.5, and 0%-3.0% (w/v) NaCl under the tested conditions, and the activity increased with time over the 180-min incubation period. In addition, the crude enzyme hydrolyzed potato starch more actively than corn and wheat starch, and was stable at temperatures ranging from 15 ℃ to 45 ℃ for 2 h. This report provides a basis for additional studies of marine yeasts that will facilitate industrial applications.

• KSBB Journal
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• v.17 no.2
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• pp.176-181
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• 2002

Astaxanthin (3,3＇-dihydroxy-${\beta}$, ${\beta}$-carotene-4-4＇-dione), a natural pigment of pink to red color, is widely distributed in nature particularly in the skin layer of salmonoids and the crust of shrimp, lobster, etc. Recently, it was produced from the yeast culture of Phaffia rhodozyma. Because of its high thermal stability and antioxidant functionality, its applications can be extended into food, cosmetics, and pharmaceutical ingredient beyond the traditional feed additive. Because of its very high lipophilicity, astaxanthin has been extracted traditionally by strong organic solvents such as chloroform, petroleum ether, acetone, etc. In this study, we developed a surfactant-based solubillization system for astaxanthin, and used it to extract astaxanthin from disrupted yeast cells. Among Tween 20, Triton X-100 and SDS, Tween 20 was identified as the most suitable surfactant in terms of extraction capacity and safety. The ethylene oxide group of Tween 20 was identified as the most significant factor to increase the HLB value that determined the extraction capacity. The effects of micelle formation condition, such as the molar ratio of astaxanthin and Tween 20, pH, and ionic strength were also investigated. pH and ionic strength showed no significant effects. The optimal molar ratio between astaxanthin and Tween 20 was 1 : 12. Antioxidant activity of astaxanthin was higher than ${\beta}$-carotene and ${\alpha}$-tocopherol. Astaxanthin in the crude extract from the yeast cell was more resistant to air and/or light degradation than pure astaxanthin, probably because of the presence of other carotenoids and lipids.

• The Korean Journal of Mycology
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• v.48 no.2
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• pp.161-167
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• 2020

The goal of this study was to isolate and characterize the wild yeast strains from the gut of earthworm(Eisenia andrei). The 19 yeast strains isolated from 5 gut of earthworm samples from Nanji water regeneration center in Goyang-si, Gyeonggi-do, Korea. Among them, 16 strains were recorded and 3 strains, Yarrowia deformans YP242 (=KACC48778), Sporidiobolus pararoseus YP66 (=KCTC27963) and Naganishia liquefaciens YI9 (=KACC48948) were recorded for the first time in Korea. The microbiological characteristics of these previously unrecorded yeasts were investigated. All three strains were oval-shaped, convex and smooth. However, they showed some differences in colony color and result of carbon assimilation assays. YP242 was white-colored and assimilated glycerol, L-arabinose and N-acetyl-D-glucosamine as carbon sources. YP66 was red-colored and assimilated D-Saccharose. YI9 was whitecolored and positive for 2-keto-D-gluconate assimilation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.11
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• pp.1587-1594
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• 2009

This study investigated the physico-chemical and sensory quality of Doenjang added with red pepper (Capsicum annuum L.) seed. The initial moisture content and salt content of Doenjang were 52.03-53.79% and 13.28-14.05%, respectively. The moisture and salt contents of Doenjang slightly decreased and increased, respectively, as fermentation periods increased. According to increasing fermentation periods, pH of Doenjang showed a little decreasing value although there were no difference between samples with various red pepper seed contents. On the other hand, titratable acidity of Doenjang increased as fermentation periods increased. Also, Doenjang added with red pepper seed had higher titratable acidity value than control Doenjang without red pepper seed. In the color of Doenjang, ‘L’ of lightness, ‘b’ of yellowness, and ‘a’ of redness were decreased as fermentation periods increased. Also, generally, increase of red pepper seed concentration resulted in higher values of redness (a), yellowness (b) and lightness (L) of Doenjang. Also, amino-type nitrogen content, which was 497-623 mg% in initial fermentation period samples, increased to 1,000 mg% for control and to 756~896 for red pepper added at the fermentation 120 days. In the total microbes, total cell count in the Doenjang samples was in the range of $10^7{\sim}10^8$ CFU/g regardless of fermentation periods. In contrast, yeast and mold number of Doenjang samples showed the range of $10^5$ CFU/g at the initial fermentation periods and decreased thereafter. In the sensory evaluation of Doenjang, unique Doenjang flavor increased regardless added red pepper seed as fermentation periods increased.

• KSBB Journal
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• v.14 no.6
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• pp.718-723
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• 1999

In order to treat of alkaline dye-processing wastewater, alkalophilic strains biodegrading azo dye, Acid red 1, is isolated from natural system, and optimal culture conditions are examined using response surface analysis, statistical analysis system program. 15 different species which grow in alkaline culture media are isolated from the effluent and river soil discharged from wastewater treatment plant in dye industrial complex. One strain which has the best decolorization efficiency is chosen, and named as AR-1. The result of the examination of carbon, nitrogen and phosphorus sources which have influence on growth and decolorization reveals that optimum carbon, nitrogen and phosphorus sources are 1.0% fructose, 1.0% polypeptone, 1.0% yeast extract and 0.5% $K_2HPO_4$, respectively. In order to optimize of biodegradation conditions of dye by response surface analysis, the characteristics of decolorization and cell growth according to culture temperature and time are monitered. The result shows that the one is optimum 34.77$^{\circ}C$ for 12.97 hours; the other at 34.73$^{\circ}C$ for 12.96 hours. While, optimal conditions of culture that satisfy both cell growth and decolorization are the temperatures from 32.86$^{\circ}C$ to 36.36$^{\circ}C$ and the period of 10.96 to 15.75 hours, respectively.

• Applied Biological Chemistry
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• v.16 no.2
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• pp.78-84
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• 1973

The strains of 297 yeasts were isolated in TakJoo mashes of 12 breweries not using the cultivated yeast and then brewing test with each yeast were carried out. The strains of 7 yeasts that have high fermentative ability among the isolated strains were selected and identified. The results obtained were as follows: 1) In the brewing test with the isolated yeasts of each brewery, average alcohol percentage of each mash had a little differences as $13.20{\sim}15.20$ percentage. 2) In fermentative lest, the isolated yeasts from the first stage mash and from the second stage mash showed t little differences in the average alcohol percentage of mash. 3) The fermentative test using the isolated yeasts based on TTC stain had at little differences. 4) Among 7 strains selected, strains: Dm-1, Dm-2, Y-1, and T-1 appeared TTC pink yeast; strsins:C-1, C-2 and Gs-1 appeared TTC red one. 5) It was identified that strains: Dm-1, Y-1, C-1, C-2 and T-1 were Sac. cerevisae; the strain Gs-1 were Sac. pretoriencis; strain D-2 were Sac. rouxii.

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.283-289
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• 1998

A bacterial strain KH-95 producing a high concentration of red pigment was isolated from the soil. The strain KH-95 was identified as a strain of Serratia sp. based on morphological and physiological characteristics. The optimal temperature and initial pH range for the production of pigment were 28$^{\circ}C$ and 7.0-8.0, respectively. The red pigment was purified through solvent extraction and silica gel column chromatography. Analyzing the structure of this pigment by instrumental analysis, it was identified as prodigiosin-like compound. In optimization of carbon and nitrogen sources, all carbon sources tested in this work inhibited the production of pigment except oils. Casein fumed out to be the most suitable nitrogen source for pigment production. Other nitrogen sources such as yeast extract, beef extract and peptone showed good cell growth but potently inhibited the production of pigment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.245-252
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• 2011

The combined effects of 10 kJ/$m^2$ ultraviolet-C (UV-C) with 50 ppm aqueous chlorine dioxide ($ClO_2$) on the qualities of red chicory and pak choi were examined. After the treatment, the samples were stored at $4{\pm}1^{\circ}C$ for 7 days. The combined treatment of $ClO_2$/UV-C reduced the initial populations of total aerobic bacteria in the red chicory and pak choi by 2.64 and 2.55 log CFU/g, respectively, compared to those of the control. Also, the populations of yeast and molds in the red chicory and pak choi by combined treatment were reduced by 2.41 and 2.00 log CFU/g, respectively. In addition, after 7 days of storage the total aerobic bacteria populations in the red chicory and pak choi were reduced to 3.71 and 3.93 log CFU/g, compared to 6.31 and 6.62 log CFU/g for the control, resulting in a significant decrease. Hunter L, a, and b values of red chicory and pak choi were not significantly different among the treatments. Non-thermal treatment caused a negligible change in sensory evaluation. These results suggest that the combined treatment of 50 ppm $ClO_2$ with 10 kJ/$m^2$ UV-C can be useful for maintaining the qualities of red chicory and pak choi.