• YAKHAK HOEJI
• /
• v.46 no.3
• /
• pp.203-207
• /
• 2002

The antifungal activities of the essential oils from Anthemis nobilis, Ciderus atlantica, Juniperus communis, Lavandula angustifolia, Pelargonium graveolens, Pogestemon patchouli, Rosmarinus officinalis, and Styrax tonkinensis which are recommended for the treatment of microbial infections in aromatherapy and complementary medicines were tested against Candida spp. The activities were measured by broth dilution method and disk diffusion assay. Most of the test oils inhibited growth of Candida albicans, C. utilis and C. tropicalis. Especially, the essential oil from Pelargonium graveolens and its main component, citronellol showed the strongest activity among the herbs except benzoic acid from Styrax tonkinensis which is well-known antimicrobial compound. As a result of checkerboard microtiter test. synergistic effect of citronellol, was shown when the component was combinated with ketoconazole, displaying a fractional inhibiting concentration (FIC) index of 0.37 against C. albicans.

• Journal of Digital Convergence
• /
• v.13 no.9
• /
• pp.369-375
• /
• 2015

We investigated the prevalence of fungi isolated from a university-affiliated hospital during 6 years (2006-2011) to provide relevent information for the patient management. The general characteristics of the clinical isolates and gender, age, and type of specimens were analyzed. Among a total of 163,530 requested samples to culture for the Laboratory of Clinical Microbiology, Department of Laboratory Medicine, Gyeongsang National University Hospital in the Republic of Korea, 5,387 (3.3%) showd positive results for fungi. The most prevalent isolates were Candida albicans 41.9%, Candida glabrata 15.5%, and Candida tropicalis 14.6%. Total isolates of fungi increased from 526 in 2006 to 1,145 in 2011. They were most commonly isolated from sixties (27.0%) and seventies (26.5%). The most common clinical specimen was urine (44.8%). Males (52.4%) were slightly more than females (47.6%). In the future, a nationwide survey and additional antifungal convergence drugs susceptibility results will provide more useful information.

• Microbiology and Biotechnology Letters
• /
• v.17 no.1
• /
• pp.1-7
• /
• 1989

To enhance the capability of starch fermentation of the transformant TSD-14, the heat treated protoplasts of TSD-14 were fused with the protoplasts of C. tropicalis (lys$^-$) in the presence of 30% (w/ v) PEG and 20 mM CaC1$_2$. Fusants were selected by nutritional complementation on minium medium and the fusion frequency was 4.4$\times$10$^{-5}$. All fusants tested were possessed of complemented traits concerning carbon compound assimilation, and the cell volumes of the fusants were approximately 1.5 times larger than the parental strains. The fusants were genetically very stable, and were able to hydrolyze alpha 1,4-glucosidic linkage as well as alpha 1,6-linkage of starch contrary to one of parents TSD-14, The most promising fusant FSC-14-75 produced 8.7% (v/v) of ethanol from 15% liquefied potato starch medium, but the result was enhanced to 9.3% (v/v) by addition of 0.3% peptone. The corresponding fermentation efficiency was 86.0%.

• Microbiology and Biotechnology Letters
• /
• v.6 no.4
• /
• pp.173-179
• /
• 1978

1) To study the productivity of single cell protein from the n-paraffin utilizing yeast, 235 yeast strains were isolatea from 90 samples 2) Optimum cell growth temperature of three strains selected was 40~45$^{\circ}C$ and these were identified as Candida tropicalis, Candida krusei and Torulopsis molischiana. 3) A-28 strain easily assimilated tetradecane, hexadecane and octadecane, but B-8 strain and C-15 strain assimilated more hexadecane than other n-paraffins. 4) Out of the selected three strains, the mass doubling time, specific growth rate and cell yield were 3.4~4.0 hours, 0.170~0.215, 86~98%, respectively. 5) Crude protein, fat, fiber, ash and nitrogen free extract of the selected three strains were found to be 48.2~61.2% 3.7~8.0%, 3.5~4.2%, 5.6~6.7%, 23.5~31.8%, respectively, and thiamine and riboflavin contents of dried yeast cell were 0.78~0.93 mg% and 6.03~7.3 mg%, respectively. 6) Yeast protein contained evenly most of amino acid, but the sulfur-containing amino acids were particularly low.

• Applied Biological Chemistry
• /
• v.19 no.4
• /
• pp.219-226
• /
• 1976

To meet the need of protein feed and fine more efficient ways of returning waste to resources, we have carried out the study of the production of yeast for foods and feeds from the corn starch cake. The present study includes the method for acid-hydrolysis, the selection of yeast capable of utilizing hydrolyzate of the corn starch cake, and culture condition of Candida tropicalis under the liquid culture and the semisolid culture. Obtained results were as follows. 1. Hydrochloric acid was more excellent on the hydrolysis of the corn starch cake than sulfuric acid, and the yield of sugar was maximum, 57.2%, when the corn starch cake was hydrolyzed with 1.0% of hydrochloric acid at 2.0kg/cm for 30 minutes. 2. As the acid solution content was increased, more sugar was liberatedfrom the mixture, until the acid solution-substrate ratio reached 10:1. Beyond this point, no further increase was observed. To prepare the cultural medium of semisolid fermentation, a acid solution to substrate ratio of 3:1 appeared to be optimum. 3. Out of 6 yeast strains, Candida tropicalis had excellent growth on the hydrolyzate of the corn starch cake, and optimum temperature and initial pH were $30^{\circ}C$ and 6.0 respectively. 4. Optimum liquid medium of Candida tropicalis is ures 0.3%, potassium phosphate monobasic 0.15g and magnesium sulfate 0.04g in 100ml of the hydrolyzate of the corn starch cake, while optimum semisolid medium is ammonium chloride 0.4g, potassium phosphate monobasic 0.1%, magnesium sulfate 0.04%. 5. Candida tropicalis could assimilate the sugar in the hydrolyzate up to more than 88.75%, and a yield of dry yeast reached 19.13% to the corn starch cake under the liquid culture. 6. Compared to the that of the untreated corn starch cake, the cellulose content of the semisolid fermented cake decreased by 3.76% to 14.7%, whereas dry yeast contents increased by 13.89%.

• The Korean Journal of Mycology
• /
• v.45 no.4
• /
• pp.259-269
• /
• 2017

In order to investigate the diversity of yeasts from major rivers (the Daejeoncheon, Gapcheon and Yudeungcheon) located in Daejeon city, we isolated wild yeasts by plating diluents of samples collected during the summer and winter of 2016 onto yeast extract-peptone-dextrose (YPD) medium, then identified them using Basic Local Alignment Search Tool (BLAST) analysis to compare the nucleotide sequences of the PCR amplicons for the D1/D2 domain of 26S rDNA. In total, we isolated 191 yeast strains belonging to 104 species from 148 soil or water samples from the rivers and their junctions. Candida spp. (45 strains) including Candida tropicalis (22 strains) were the most abundantly isolated strains from the Daejeoncheon. Candida spp. (16 strains) including Candida vartiovaarae (8 strains) and Candida spp. (18 strains) such as Candida sake (4 strains) were also the dominant isolates from the Gapcheon and Yudeungcheon, respectively. In conclusion, Candida spp. and Cryptococcus spp. were the most dominant strains, corresponding to 42% and 7% of the 191 yeast strains isolated in this study, respectively.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.2
• /
• pp.230-240
• /
• 2016

Information on the effects of different yeast species on ruminal fermentation is limited. This experiment was conducted in a $3{\times}4$ factorial arrangement to explore and compare the effects of addition of three different live yeast species (Candida utilis 1314, Saccharomyces cerevisiae 1355, and Candida tropicalis 1254) at four doses (0, $0.25{\times}10^7$, $0.50{\times}10^7$, and $0.75{\times}10^7$ colony-forming unit [cfu]) on in vitro gas production kinetics, fiber degradation, methane production and ruminal fermentation characteristics of maize stover, and rice straw by mixed rumen microorganisms in dairy cows. The maximum gas production (Vf), dry matter disappearance (IVDMD), neutral detergent fiber disappearance (IVNDFD), and methane production in C. utilis group were less (p<0.01) than other two live yeast supplemented groups. The inclusion of S. cerevisiae reduced (p<0.01) the concentrations of ammonia nitrogen ($NH_3$-N), isobutyrate, and isovalerate compared to the other two yeast groups. C. tropicalis addition generally enhanced (p<0.05) IVDMD and IVNDFD. The $NH_3$-N concentration and $CH_4$ production were increased (p<0.05) by the addition of S. cerevisiae and C. tropicalis compared with the control. Supplementation of three yeast species decreased (p<0.05) or numerically decreased the ratio of acetate to propionate. The current results indicate that C. tropicalis is more preferred as yeast culture supplements, and its optimal dose should be $0.25{\times}10^7$ cfu/500 mg substrates in vitro.

• KSBB Journal
• /
• v.17 no.1
• /
• pp.93-99
• /
• 2002

Two-stage fed-batch culture of Candide tropicalis that was designated primarily to cultivate the cell in the glucose medium (1st stage) and then produced the xylitol from xylose medium (2nd stage) was developed to improve a xylitol yield and productivity. In the growth stage, glucose was automatically supplied to the fermentor by pH-stat mode when the pH was up 5.7, When a feeding medium was added in order to reach the glucose and yeast extract concentrations up to 100 and 40 g/L, respectively, a high cell concentration and a relatively low ethanol concentration were obtained in 18.5 h culture. In the production stage, initial xylose concentration of 150 g/L was the most favorable for obtaining the final xylitol concentration and productivity. The addition of mineral salts was also enhanced a xylitol production. But the aeration rate was not significantly affected a xylitol production. When the addition of 16 g yeast extract and 232.5 g xylose powder at the production stage was used, xylitol yield and productivity were significantly increased. With these conditions, xylitol concentration, yield and productivity of 108.9 g/L, 74%) and 3.3 g/L·h, respectively, were obtained in a final volume of 1.58 L. The further addition of 16 g yeast extract and 232.5 g xylose powder increased the working volume partly (1.67 L) and resulted in a relatively high xylitol concentration, yield and productivity of 193 g/L, 70% and 3.6 g/L·h, respectively.

• Applied Microscopy
• /
• v.23 no.2
• /
• pp.97-106
• /
• 1993

This study was done to elucidate the electron microscopic characteristics of certain pathogenic fungi. Four Candida species, (C. albicans, C. tropicalis, C. parapsilosis and C. glabrate) and Cryptococcus neoformans were cultured for 3 days at $30^{\circ}C$ in the Sabouraud dextrose medium. After incubation, they were stored at $4^{\circ}C$ for 24hours. Fine structures were analyzed by morphometry, and Tukey's HSD test was used for statistics. On scanning electron microscopy C. albicans and C. neoformans were similar in size but different in shape, showing sphero-shape or ovalo-shape in C. neoformans. Surface of C. neoformans was coarse and spiny, but Candida species examined were uniformly smooth. In size, C. glabrata was the smallest among them. Budding scar as seen on the surface of Candida species by the number ranging from 1 to 7. Cryptococcus neoformans showed one or two budding scar. On transmission electron microscopy the cytoplasm of most yeast cells showed plentiful glycogen particles, mitochondria, peroxisomes and vacuoles. However, cell walls were different among four Candida species and Cryptococcus neoformans. The cell wall of Candida species consisted of fibrous layer, that was electron dense layer and transparent layer, in contrast to Cryptococcus neoformans consisted of electron dense layer with lamellar structure. This layer was two times thicker than that of Candida species. The outer layer of cell wall was of radiating pattern.

• Mycobiology
• /
• v.30 no.1
• /
• pp.27-30
• /
• 2002

Two-hundred two yeast strains were isolated from rhizosphere(87 strains) and nonrhizosphere(115 strains) areas of potato, maize, vegetable marrow, and cabbage plants. On the basis of 26 morphological and physiological properties, the isolated yeast strains were assigned to 9 genera and 15 species. Trichosporon beigelii, Kluyveromyces marxianus and Torulaspora delbrueckii were the dominant species. Cryptococcus humicolus and Candida tropicalis were represented by considerable numbers of strains. Of low occurrence were Saccharomyces cerevisiae and Candida blankii. Other yeast species were represented by single or two strains. Total counts of yeast cells per gram dry soil ranged from $1.1{\times}10^3$ to $6.6{\times}10^3$ in soil samples of rhizosphere areas and from $6.5{\times}10^2$ to $5.6{\times}10^3$ in soil samples of nonrhizosphere areas. Types of the tested plants affected not only the total counts of yeast cells but also spectra of yeast species. Relationships of age of potato plant, moisture contests of soil samples, and its pH values and total counts of yeast cells were discussed.