• Korean Journal of Food Science and Technology
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• v.25 no.2
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• pp.191-195
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• 1993

The intestinal microflora of humans is an extraordinarily complex mixture of microorganisms, the majority of which are anaerobic bacteria. Amongst them, most prevalent bacteria are Bacteroides, Eubacterium, Peptococcus, Bifidobacteria. We isolated a Bacteroides fragilis strain from a Korean adult and examined various glycosidase activities of this strain. The activities of $N-acetyl-{\beta}-glucosaminidase,\;{\alpha}-fucosidase$, ${\beta}-glucuronidase$, chitobiase and PNPCase were stronger in Bacteroides fragilis Roid 8 than in other intestinal anaerobic bacteria. $N-acetyl-{\beta}-glucosaminidase$ was strongest, followed by ${\alpha}-fucosidase$, ${\beta}-glucuronidase$ and PNPCase. The activities of ${\beta}-galactosidase$, ${\beta}-xylosidase,\;{\alpha}-arabinofuranosidase$ were not present or very low. The activities of ${\alpha}-glucosidase$, ${\beta}-glucosidase$ and ${\alpha}-galactosidase$ were present but at a lower level than in Bifidobacterium. The effect of the carbon sources on the production of $N-acetyl-{\beta}-glucosaminidase$, ${\alpha}-fucosidase$, ${\beta}-glucuronidase$ and PNPCase of Bacteroides fragilis Roid 8 was investigated. :.actose and glucose lowered the production of the varous glycosidase enzymes studied in this work. In addition, we investigated the optimum temperature and pH of each glycosidase from Bacteroides fragilis Roid-8 using crude enzyme preparations.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.463-468
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• 2000

This study was conducted to investigate the effects of Kluyveromyces fragilis, Candida utilis and brewer's yeast as an additive in formulated diets containing different fish meal levels ($55{\%} and 45{\%}$) on growth and body composition of juvenile Korean rockfish (Sebastes schlegeli). Juvenile rockfish (average weight, 2.6 g) were distributed into 24 tanks with 3 replication groups and fed eight isoproteic ($41{\%}$) and isolipidic ($11{\%}$) diets containing each level ($3{\%}$) of K. frayilis, C. utilis and brewer's yeast as an additive. Survival rate of fish was not affected by dietary fish meal level and yeast kind (P > 0.05). Weight gain of fish fed the control and diets containing C. utilis and brewer's yeast was not influenced by fish meal level (P > 0.05), Weight gain of fish fed the $55{\%}$ fish meal diet containing C. utilis and $45{\%}$ fish meal diets containing K. fragilis and C. utilis was lower than that of fish fed the control diet (P < 0.05). Feed efficiency and protein efficiency ratio of fish fed the control and diet containing brewer's yeast were not affected by fish meal level, but these value of fish fed the diets containing K, fragilis and C. utilis were lower in $45{\%}$ fish meal diets than in $55{\%}$ fish meal diets. Hepatosomatic index and liver lipid content of fish fed the diet containing C. utilis were decreased regardless of fish meal level (P < 0.05), Hemoglobin, hematocrit, red blood cell, plasma total protein and plasma total glucose were not affected by dietary fish meal levels and yeast supplements (P > 0.05). From the above results, it can be concluded that yeast supplement in this formulated diet for growth of juvenile rockfish is not necessary.

• KSBB Journal
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• v.4 no.2
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• pp.172-176
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• 1989

The alcohol fermentation was carried out to study the effect of aeration and unsaturated fatty acids added on the ethanol tolerance of Saccharomyces cerevisiae STV89 and Kluyveromyces fragilis CBS397. The cell growth rate and ethanol production rate was stimulated by aeration and the cell mass production and ethanol production were also substantially improved. With respect to strains, the maximum specific growth rate and overall ethanol productivity of K. fragilis under aerated condition were 6.4 fold and 4.4 fold higher than those of strictly anaerobic condition, although those of S. cerevisiae were increased 1.7 times and 2.3 times by aeration. The addition of ergosterol, linoleic acid and oleic acid also improved the cell growth and ethanol production of S. cerevisiae and K. fragilis. Thus it was found that oxygen and unsaturated fatty acids added played a decisive role on the increase of ethanol tolerance of yeast strains.

• KSBB Journal
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• v.20 no.5 s.94
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• pp.355-358
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• 2005

Bacteroides is the most predominant bacteria in the human large intestinal tract. Bacteroides fragilis RoidB isolated from a Korean faecal sample showed high $\alpha-fucosidase$ activity compared to other bacterial species. The optimized meidum for the production of $\alpha-fucosidase$ from 8. fragilis contained BHI 37g, hemin 10mg, cysteine 0.5g, resazurin 1mg, vitamin K1mg, and starch 5g per 1 L. The crude $\alpha-fucosidase$ obtained through DEAE-sepharose and CM- cellulose chromatography showed optimum temperature and pH at $40^{\circ}C$ and 7.0, respectively. Among several metals, $Co^{++}\;and\;Zn^{++}$ showed strong inhibition on enzyme activity.

• The Korean Journal of Mycology
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• v.26 no.3 s.86
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• pp.293-301
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• 1998

Taxonomical studies of soil-borne fungi were performed. Soil samples were collected from greenhouses located in Jinju-City, Korea. Soil dilution plating method was adopted for the pure isolation. Seven ascomycetous fungi were isolated from the soil samples, and subsequently identified. Among them, five isolates, Chaetomium brasiliense, C. indicum, Corynascus sepedonium, Petriella sordida, and Thielavia fragilis have never been reported in Korea. Both teleomorphic and anamorphic states were observed in the two species, Corynascus sepedonium and Petriella sordida, and only teleomorphic state was observed in Thielavia fragilis, Chaetomium indicum, and Chaetomium brasiliense. Illustrated descriptions are presented for the isolates examined in the present study.

• Korean journal of food and cookery science
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• v.15 no.1
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• pp.73-80
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• 1999

This study was carried out to investigate the effects of enzyme treatments on the functional properties of soy protein isolate (SPI) and to examine the quality attributes of soy yogurt prepared by different enzyme treatments, sweeteners and starter cultures. Enzyme treatment increased the solubility and emulsifying capacity of soy proteins, but decreased the emulsifying stability; the enzymatic activity of ${\alpha}$-chymotrypsin was higher than that of trypsin. Enzyme treatments decreased the pH of soy yogurts prepared by both culture methods, the culture of L. bulgaricus and S. thermophilus and the culture of L. bulgaricus and K. fragilis, but increased the titratable acidity, total numbers of lactic acid bacteria and yeast. Trypsin was more effective than ${\alpha}$-chymotrypsin in decreasing pH and increasing titratable acidity and total numbers of lactic acid bacteria and yeast. Fructose decreased the pH of soy yogurts more than sucrose in the culture of L. bulgaricus and S. thermophilus, and vice versa in the culture of L. bulgaricus and K. fragilis. Fructooligosaccharides were more effective in the culture of L. bulgaricus and K. fragilis than in the culture of L. bulgaricus and S. thermophilus in increasing the titratable acidity, total count of lactic acid bacteria and yeast. In sensory evaluation, soy yogurts containing trypsin treated SPI, fructose and fructooligosaccharides (75%:25%) were more acceptable than those containing untreated or trypsin treated SPI and fructose. This was because of more smooth and less sour, in which the values of pH, titratable acidity, microbial growth, and viscosity were in the range of commercial yogurts. Soy yogurts fermented by L. bulgaricus and K. fragilis showed more smooth mouthfeel than those fermented by L. bulgaricus and S. thermophilus.

• The Korean Journal of Mycology
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• v.41 no.1
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• pp.33-37
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• 2013

To develop the functional pear fruitlet product, we prepared fermented pear fruitlet product (FPFP) from mixed fermentation of Saccharomyces cerevisiae, Kluyveromyces fragilis and Lactobacillus plantarum. Then, we investigated their several physiological functionalities. Among several physiological functionalities, antihypertensive angiotensin I-converting enzyme (ACE) inhibitory activity of the FPFP was the highest of 87.4% and its antioxidant activity was also showed 69.6%. FPFP from mixed fermentation by yeasts and Lactobacillus plantarum after thawing of frozen pear at $20^{\circ}C$ showed higher physiological functionalities than those of single fermentation by Saccharomyces cerevisiae or Bacillus subtilis after $40^{\circ}C$ of thawing.

• Journal of Microbiology and Biotechnology
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• v.2 no.2
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• pp.108-114
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• 1992

The fermentative characteristics in ethanol production from lactose, with increased ethanol tolerance, of a fusant yeast strain constructed by protoplast fusion of Saccharomyces cerevisiae and Kluyveromyces fragilis were studied. The ethanol tolerance of this strain was increased to 8.0%, compared with the parent K. fragilis. During batch ethanol fermentation the optimal cultivation conditions for this fusant yeast were an initial pH of 4.5, a culture temperature $30^\circ{C}$. stirring at 100 rpm without aeration in 10% lactose medium (supplied with 1.0% yeast extract). Using this fusant strain in whey fermentation to ethanol, maximum ethanol production reached 3.41% (w/v) (theoretical yield; 66.7%) after a 48 hour cultivation period.

• ALGAE
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• v.28 no.1
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• pp.53-62
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• 2013

Actinotrichia is a calcified galaxauracean red algal genus with temperate and tropical distributions in the Indian and Pacific Oceans. Morphological characteristics, along with rbcL and cox1 sequences, were analyzed from specimens collected in the western Pacific and the Indian Oceans. Both rbcL and cox1 data confirmed the occurrence of A. fragilis, A. robusta, and Actinotrichia sp. in this region. The presence of A. fragilis was verified in tropical Indo-Pacific and temperate northeast Asian waters and was characterized by high genetic diversity. Although A. robusta commonly occurs in the East China Sea, we confirmed its presence on rocks and crustose algae in the subtidal zone of three islands in the Andaman Sea. Actinotrichia sp. was similar to A. calcea in morphology and distribution, but with sufficiently different sequences, thus, additional sampling over the range will enable a more realistic evaluation of its taxonomic status.

• ALGAE
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• v.21 no.1
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• pp.15-48
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• 2006

The genus Martensia (Delesseriaceae, Rhodophyta) is characterized by thalli composed of one to several blades that consist of proximal membranous sections and distal latticework. Nerves or veins are absent in the membranous sections. The life cycle of Martensia is accomplished by isomorphic alternation of generations. The gametophytes of Martensia are dioecious, and the male and female gametangial plants are morphologically similar. The type species of Martensia is M. elegans Hering. In this study, nine species were confirmed to occur in the subtidal regions of Jeju Island, Korea: M. albida sp. nov., M. australis Harvey, M. bibarii Y. Lee, M. elegans Hering, M. flammifolia sp. nov, M. fragilis Harvey, M. jejuensis Y. Lee, M. palmata Y. Lee, and M. projecta Y. Lee. Three of these, M. australis, M. fragilis, and M. elegans, are new records in the flora of Korea. The results of molecular analyses of the internal transcribed spacer (ITS) 1 region in the nrDNA showed that M. elegans is identical to M. australis, and M. fragilis coincides with M. bibarii. It may be a less effective tool for the species discrimination in Martensia.