• Journal of Microbiology and Biotechnology
• /
• v.10 no.6
• /
• pp.776-783
• /
• 2000

Various alcohol yeast strains have been isolated from main mashes of Korean traditional liquors, and their genetic diversities were previously reported [23]. In this study, the strain SHY111, showing the highest alcohol production, was tested for its fermentation and sporulation characteristics. Additionally, its haploid cells were isolated and tested for their growth and fermentation patterns. The strain was identified as Saccharomyces cerevisiae based on its morphological and physiological characteristics. The sequences of the ITS(internal transcribed spacer) and 5.8S rDNA regions of S. cerevisiae SHY111 were found to be identical to those of S. cerevisiae that was obtained from through the yeast genome project. The maximum fermentation ratio obtained by the strain SHY111 (96.7%) was almost the same as that by S. cerevisiae Balyun No. 1 (96.5%) that was a little higher than that by S. cerevisiae KCCM11215(95.8%). The strain was induced for sporulation in a sporulation liquid medium using log phase cells grown in different types of pre-sporulation media, and its haploid cells were obtained by spore dissection using a micromanipulator. The majority of the spores formed a small colony on a YPD agar plate, and the haploid yeast cells derived from the strain SHY111 showed a variety of growth and alcohol fermentation patterns. It was proposed that the fermentation patterns were related to their growth phenotypes in the most haploid strains, but possible not in some strains.

• The Korean Journal of Mycology
• /
• v.24 no.4 s.79
• /
• pp.280-292
• /
• 1996

The fungal isolates of Mucorales, directly collected from Korean traditional raw materials of Nuruk (raw material for Korean rice wine) and Meju (raw material for Korean soysauces), were compared with those of Rhizopus oryzae purchased. The fungal isolates of Rhizopus, Mucor, and Absidia mostly identified as based on the morphological observations, were evaluated with the PCR-polymorphic bands. The PCR-polymorphic bands of the genomic DNA reacted with the primers of OPD series tenmer were various, but showed averaged 4 to 6 in the agarose-electrophoresis. The dissimilarity coefficient (DC) between two isolates were compared by the cluster analyses, dendrogams and polar ordinations. The isolates of R. oryzae known. showed several groupings within the lower value of DC and were divided to two groups of amylo-process and other fungi with other purposes. The isolates unidentified were identified by the DC made of this results. Taxonomy of these isolates made by the morphological observations were consistent with those resulted above in most case but not in all aspects. More works were needed with the isolates known for detail informations of Mucorales.

• Mycobiology
• /
• v.41 no.3
• /
• pp.139-144
• /
• 2013

Makgeolli is a traditional cloudy-white Korean rice wine with an alcohol content of 6~7%. The present study investigated the morphological characteristics, carbon-utilizing ability, fatty acid composition, alcohol resistance, glucose tolerance, and flocculence of Saccharomyces cerevisiae Y98-5 and Pichia anomala Y197-13, non-S. cerevisiae isolated from Nuruk, which is used in brewing Makgeolli. Similar morphological characteristics were observed for both isolated wild yeast strains; and the carbon source assimilation of Y197-13 differed from that of other P. anomala strains. Strain Y197-13 was negative for D-trehalose, mannitol, arbutin, I-erythritol, and succinic acid. The major cellular fatty acids of strain Y197-13 included C18:2n6c (33.94%), C18:1n9c (26.97%) and C16:0 (20.57%). Strain Y197-13 was Crabtree-negative, with 60% cell viability at 12% (v/v) ethanol. The flocculation level of strain Y197-13 was 8.38%, resulting in its classification as a non-flocculent yeast.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.12
• /
• pp.1749-1757
• /
• 2012

Makgeolli is a traditional rice wine favored by the general public in Korea. This study investigated the fermentation and sensory characteristics of using wild yeast strains for brewing makgeolli. A non-Saccharomyces cerevisiae strain was isolated from nuruk and termed Y197-13. It showed 98% similarity to Pichia anomala and had an optimal growth temperature of $25^{\circ}C$. Makgeolli was manufactured using koji, jinju nuruk, and improved nuruk as fermentation agents. Y197-13 makgeolli brewed with koji had alcohol and solids contents of 11.1% and 13.9%, respectively. Sweet sensory characteristics were attributed to residual sugars in makgeolli with 6% alcohol. The makgeolli had a fresh sour taste and carbonated taste. Volatile component analysis showed the isoamyl alcohol, phenylethyl alcohol, isoamyl acetate, and fatty acid, including ethyl oleate and ethyl linoleate, relative peak area was higher in Y197-13 makgeolli than in makgeolli with Saccharomyces cerevisiae. These results suggest the wild yeast, Y197-13, as a candidate for brewing makgeolli.

• Korean Journal of Food Science and Technology
• /
• v.39 no.5
• /
• pp.546-551
• /
• 2007

The physicochemical characteristics and sensory properties of Jinyangju were investigated at different degrees of milling (DOM; 0, 5, 7, and 10%) of waxy glutinous rice after 2 weeks of fermentation. The final pH values were 3.50, 3.84, 4.16, and 4.21 at the DOMs of 0, 5, 7, and 10%, respectively. The final total acidities were 1.21, 1.16, 0.94, and 0.91%; final total sugar contents were 6.38, 6.51, 5.54 and 5.40%; and final alcohol contents were 14.50, 14.50, 15.50, and 15.40%, respectively. Hunter L-value of the DOM 5% rice was lower those of the DOM 7% and 10% rice, but its Hunter b-value was higher than those of the DOM 7% and 10% rice. However, Hunter a-value of the Jinyangju were not significantly different among the samples (p>0.05) Hunter L-value. The Jinyangju made with the DOM 7% rice showed the highest overall sensory preference.

• The Korean Journal of Food And Nutrition
• /
• v.26 no.4
• /
• pp.633-637
• /
• 2013

There is an increasing consumption of Makgeolli in both domestic and foreign markets due to a high interest in Korean traditional alcoholic beverages. However, currently, a standardized system of manufacturing, storing and circulating Makgeolli is not available. Therefore, manufacturing the constant quality of finished products is hardly achieved due to the uncertified quality index of Makqeolli. In particular, quality changes occur as a result of variable initial load of microorganisms during shelf life. Eight different commercially available brands of Makgeolli were obtained, and their initial concentrations of yeasts were measured. One brand with the highest concentration was chosen, and the variable initial concentrations were prepared at a concentration of $10^6{\sim}10^8$ yeast CFU/ml. These Makgeolli samples were heat-treated at 65, 70, 75 or $80^{\circ}C$. It was shown that temperatures higher than $75^{\circ}C$ were needed in order to pasteurize Makgeolli properly. In addition;it is considered that controlling the microorganisms by a standardized system for the processing analysis would improve the quality of Makgeolli.

• Applied Biological Chemistry
• /
• v.28 no.3
• /
• pp.196-201
• /
• 1985

Several interesting aromas could be produced from the cultures of Saccharomyces cerevisiae depending on the amino acids used as sole nitrogen source. The yeast produced a fusel oil odor in leucine-medium, an aroma of traditional Korean rice wine in aspartic acid-medium and a floral note in phenylalanine-medium, respectively, Ethanol, iso-amyl alcohol, iso-butanol and n-propanol were found as major volatile con stituents in all the above three cultures. In addition to these compounds, phenethyl alcohol was present as major volatiles both in the aroma concentrates of the phenyl alanine and aspartic acid cultures, and phenethyl acetate only in the phenylalanine culture.

• Korean Journal of Microbiology
• /
• v.31 no.2
• /
• pp.99-104
• /
• 1993

Two strains of the gram-negative acetic acid bacteria, Acetobacter sp. strain CS2- AND CS5, were isolated form the traditional raw rice wine vinegar of Haenam area. The strains oxidized ethanol to acetic acid and over-oxidized acetate and lactate to $CO^{2}$ and $H ^{2}$O. They produced 2-ketogluconic acid from glucose but did not produce .gamma.-pyrones from glucose and dihydroxyacetone from glycerol. The CS strains possessed ubiquinone-9 as a major isoprenoid quinone and contained straight-chain $C_{18 :1}$, $_C{16 : 0}$, and $C _{14 : 0}$ fatty acids. The DNA base composition of the CS2 and CS5 strains was 56.2 and 57.3 mole% G + C, respectively. The isolates were grown well on methanol, gluconate, erythritol, raffinose, dulcitol and xylitol as sole sources of carbon and energy which are different from those of other Acetobacter species and producedd acid from sucrose, glycerol, fructose, inositol, mannitol, and ribose.

• Korean Journal of Food Science and Technology
• /
• v.44 no.6
• /
• pp.728-735
• /
• 2012

Makgeolli is the oldest Korean traditional wine made from rice, and contains 6-8% alcohol. Also, nuruk is traditionally prepared by exposing moistened ground wheat or rice to the air, and there contained airborne microorganism. In this study, purple sweet potato (PSP) was used as a raw material in the rice nuruk- and makgeolli-making processes. PSP rice nuruk (RN) was made with rice and 0-10% (w/w) PSP, and the characteristics of makgeolli were studied during fermentation. The pH during fermentation decreased from 4.27 (0% PSP-RN), 4.59 (2.5%), 4.50 (5.0%), 4.46 (7.5%), and 4.43 (10.0%) of initial fermentation day to 4.12, 3.82, 3.67, 3.71, and 3.66, respectively, at day 7. The sugar contents increased from $0.4^{\circ}Bx$ of the initial day to $8.0-8.4^{\circ}Bx$, and the levels of alcohol increased to 13.0% (0% PSP-RN), 13.2% (2.5%), 12.8% (5.0, 7.5, and 10.0%) by day 7, respectively. In addition, the contents of soluble anthocyanins and phenolics increased from 0.001-0.121 and 0.2-0.27 g/L on the initial fermentation day to 0.002-0.166 and 1.65-1.87 g/L, corresponding to increases in levels of antioxidant activities of 20-50%, respectively.

• Korean Journal of Food Science and Technology
• /
• v.46 no.6
• /
• pp.702-709
• /
• 2014

Normal alcoholic fermentation took place at $20-25^{\circ}C$ in yakju (traditional Korean rice wine) prepared without the addition of protease (non-addition group). The total concentration of organic acids increased by 1.0-2.7 fold in the non-addition group. While the concentration of lactic acid and acetic acid increased, the pyroglutamic acid concentration decreased by 51.1 fold. Consequently, the total acidity and volatile acid concentration increased, and the overall pH decreased. Compared to the addition group, the non-addition group showed a 3.0-5.2 fold increase in the amount of amino acids; however, the total estimated concentrations of free-form amino acids were 5.2-11.9 times lower than those in the latter group. The major amino acids found in the non-addition group were alanine, arginine, leucine, and phenylalanine. The yakju preparation from the non-addition group showed a 1.2-3.0 fold decrease in the final color intensity as compared to that from the addition group.