• Food Science of Animal Resources
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• v.29 no.1
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• pp.15-23
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• 2009

In order to develop a new starter for fermented milk, 2082 bacteria were isolated from raw milk. The strain that showed excellent acid forming and ${\gamma}$-aminobutyric acid (GABA) production ($711.40{\mu}g/g$ D.W) characteristics after incubation at $37^{\circ}C$ for 18 hr was selected and identified as Lactobacillus acidophilus by the result of API carbohydrate fermentation pattern and 16S rDNA sequence. L. acidophilus RMK567 was investigated for its physiological characteristics. RMK67 strain showed good GABA production compared with commercial lactic acid bacteria. The optimum growth temperature of L. acidophilus RMK567 was $40^{\circ}C$ and cultures took 15 hr to reach pH 4.3. L. acidophilus RMK567 showed higher sensitivity to penicillin-G, novobiocin, as compared to other 14 different antibiotics. However, it showed more resistance to kanamycin, neomycin, streptomycin. It showed higher leucine arylamidase and ${\beta}$-galactosidase activities compared to 16 other enzymes. It was comparatively tolerant to bile juice and able to survive at pH 2 for 3 hr. It showed resistence to Escherichia coli, Salmonella typhimurium and Staphylococcus aureus with rates of 29.2%, 39.1% and 51.4%, respectively. Based on these and previous results, L. acidophilus RMK567 could be an excellent starter culture for fermented milk with excellent GABA contents.

• Journal of Nutrition and Health
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• v.37 no.8
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• pp.633-644
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• 2004

This study was performed to investigate effect of dried powders and ethanol extracts of garlic flesh and peel on antioxidative capacity in 16-month- old rats. Forty Sprague-Dawley male rats weighing 618.1$\pm$6.5g were blocked into five groups according to body weight and raised for 3 months with experimental diets containing 5% (w/w) of dried powders of garlic flesh or peel, or ethanol extracts from equal amount of each dried powder. Total polyphenols, flavonoids, /3 -carotene, vitamin C, vitamin E, and total antioxidant status (TAS) levels were determined in garlic preparations. Thiobarbituric acid reactive substances (TBARS) levels in plasma, liver and VLDL + LDL fraction, oxidative DNA damage (8-hydroxy-2' -deoxyguanosine, 80HdG) in kidney, xanthine oxidase (XO) activities in plasma and liver, superoxide dismutase (SOD) activities in erythrocyte and liver, and carotenoid concentration, and total antioxidant status (TAS) in plasma were measured. Total polyphenols and flavonoids contents in garlic preparations were highest in peel ethanol extract. Vitamin C content was not different significantly among preparations, but peel powder contains slightly more vitamin C. The content of $\beta$-carotene was highest in peel ethanol extract and vitmain E content was highest in flesh ethanol extract. The highest level of TAS was observed in peel ethanol extract. Plasma TBARS levels in all the experimental groups were found to be significantly lower than control group, and TBARS concentration in VLDL + LDL fraction was decreased in all the experimental groups in comparison to control group. Also levels of 80HdG in kidney in experimental groups were lower than that of control group. Plasma and liver XO activities were. decreased in all experimental groups, and erythrocyte and liver SOD activities were higher in experimental groups compared to control group. All experimental groups also showed higher plasma TAS levels than control group. Especially, garlic flesh powder group was significantly lower in plasma and liver XO activities, and significantly higher in erythrocyte and liver SOD activities than control group. Moreover, plasma TBARS level and kidney 8OHdG level were decreased in flesh powder group. In conclusion, garlic diets showed effect of improving antioxidative capacity in 16-month old rats, especially, garlic flesh powder was prominent in inhibiting XO activity, promoting SOD activity and decreasing kidney 8OHdG level among experimental groups.

• Korean Journal of Microbiology
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• v.43 no.2
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• pp.124-129
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• 2007

We evaluated the use of citrus fruit fermented by lactic acid bacteria, as a feed supplement for flounder (Paralichthys olivaceus) cultivation. For the fermentation, a lactic acid bacterial strain W-44 showing antibacterial activity was isolated from kimchi. From the phylogenetic analysis based on, 16S rDNA sequence, the strain W-44 was identified as Lactococcus lactis. After the fermentation of citrus fruit with L. lactis W-44, the contents of naringenin and hesperetin, bioactive flavonoid aglycones, were increased about ten-fold and six-fold, respectively. The effects of fermented citrus fruit-based feed additives (CFBFA) were tested on the growth of flounder, Paralichthys olivaceus. There were significant differences in average total length and body weight between the experimental and control group. The growth rate of the experimental group fed with the 0.2% CFBFA-supplemented diet was increased 4.5% and 20.9% more than the control group in total length and body weight, respectively. These results suggest that the fermented citrus fruit could be used as a functional feed additive for flounder cultivation.

• Korean Journal of Microbiology
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• v.43 no.3
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• pp.217-221
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• 2007

The domestic cultured Campbell's Early and Geubong grapes were fermented far the production of red wines with the isolated wild yeast Saccharomyces cerevisiae IJ850. For the isolation of wild yeast, Geubong and Campbell's Early grapejuices were naturally fermented at room temperature for 6 days without adding stater culture. The strain isolated from Geubong which has 1.8 times higher fermentative ability than the strains isolated Campbell Early was selected. The selected strain was identified by using 26S rDNA sequencing. The strain showed 99.7% of similarity with Saccharomyces cerevisiae and thus identified as Saccharomyces cerevisiae IJ850. It was investigated the fermentative ability as the start culture. For the production of grapewine, the final sugar concentrations of grapejuices were adjusted to the $25^{\circ}Brix$ with anhydrous glucose. The grapejuices were fermented at room temperature for 10 days in the air-locked bottles filled with $CO_2$ gas. The final yield and alcohol concentration of Campbell's Early and Geubong grapewines fermented with the isolated wild yeast were 80.8%, 11.0% and 87.8%, 13.0%, respectively. Between the isolated wild yeast S. cerevisiae IJ850 and the commercial yeast S. cerevisiae EC1118, total acidities of grapewines produced with wild yeast were lower than those produced with the commercial yeast. The pH values and the values of color analysis of grapewines produced with both strains were similar. The total phenol contents of campbell's Early and Geubong wines produced with the isolated yeast and the commercial yeast were obtained in the range of 75 to 125mg/L. In conclusion, S. cerevesiae IJ850 isolated from the domestic cultured Geubong grape is able to use to produce grapewines as stater culture.

• The Korean Journal of Mycology
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• v.42 no.2
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• pp.159-164
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• 2014

For development of a method for differentiation of Pleurotus eryngii cultivars, simple sequence repeats (SSR) from whole genomic DNA sequence analysis was used for genotyping and two multiplex-SSR primer sets were developed. These SSR primer sets were employed to distinguish 12 cultivars and strains. Five polymorphic markers were selected based on the genotyping results. PCR using each primer produced one to four distinct bands ranging in size from 200 to 300 bp. Polymorphism information content (PIC) values of the five markers were in the range of 0.6627 to 0.6848 with an average of 0.6775. Unweighted pairgroup method with arithmetic mean clustering analysis based on genetic distances using five SSR markers classified 12 cultivars into two clusters. Cluster I and II were comprised of four and eight cultivars, respectively. Two multiplex sets, Multi-1 (SSR312 and SSR366) and Multi-2 (SSR178 and SSR277) completely discriminated 12 cultivars and strains with 21 alleles and a PIC value of 0.9090. These results might be useful in providing an efficient method for the identification of P. eryngii cultivars with separate PCR reactions.

• Food Science and Preservation
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• v.20 no.5
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• pp.705-711
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• 2013

Gamma amino butyric acid (GABA), known as a non-protein amino acid and major inhibitory neurotransmitter in the brain, has several functional properties such as neurotransmission, induction of hypotension, tranquilizer, and diuretic effects. The purpose of this study was to isolate and identify lactic acid bacteria, producing high GABA in fermented soy curd. Thirty-two strains of tofu-forming lactic acid bacteria were isolated from kimchi which a traditional Korean food fermented with many kind of microorganism. Among 32 strains, four strains (strain No. 10, 104, 214, 249) formed firm soycurd. In order to select lactic acid bacteria having high GABA producing potential, the isolated strains were cultured in the soymilk and fermented for 48 hr at $37^{\circ}C$. A strain No. 383, which showed highest GABA contents in fermented soycurd, was identified as L. sakei by 16S rDNA sequencing and API analysis, and named as L. sakei 383. L. sakei 383 showed optimal growth up to 24 hr at $35^{\circ}C$ in MRS broth. The optimal time and temperature for GABA production were 18 hr and $35^{\circ}C$ in soymilk. In the optimal condition time and temperature, GABA content of fermented soycurd by L. sakei 383 was 8.65 mg/100 g.

• Food Science and Preservation
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• v.20 no.5
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• pp.684-690
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• 2013

The antioxidant and photoprotective effects of various extracts from the roots of Rumex crispus L. were evaluated. The concentrations ($IC_{50}$) of various extracts required to exert a 50% reducing effect on a DPPH radical were found to be 0.005~0.093 mg/mL. The ethyl acetate extract showed a more remarkable effect than the positive control ascorbic acid. The concentrations ($QC_{50}$) of the butanol and ethyl acetate extracts required to exert a 50% reducing effect on the singlet oxygen $^1O_2$ were found to be 0.464 and 0.365 mg/mL, respectively. Both extracts were also found to protect the in vitro biological system from the detrimental effect of a singlet oxygen $^1O_2$ on type II photosensitization in E. coli and genomic DNA. Among all the tested extracts, the ethyl acetate and butanol extracts contained higher amounts of total phenolic contents. The results suggest that our study may contribute to the development of new bioactive products with potential applications to the reduction of photo-produced oxidative stress involving reactive oxygen species in living organisms.

• Applied Biological Chemistry
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• v.42 no.1
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• pp.12-19
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• 1999

To improve biopolymer productivity and properties of Bacillus strains, protoplast fusion was performed between biopolymer producing Bacillus subtilis K-1 and lactose utilizing Bacillus coagulans. The results were as follows; Protoplasts mixed in fusion fluid containing 33% PEG 6000, 1% PVP and 10 mM $CaCl_2$ were reacted for 5 min at $37^{\circ}C$ and then centrifused protoplasts were directly overlaid on the selective media containing $100\;{\mu}g/ml$ antibiotics and incubated for 3 days. At this conditions, the frequency of protoplast fusion was generally in the range of $4.6{\times}10^{-5}\;to\;1.8{\times}10^{-7}$ in ratio. Segregation ratio was observed between 1 to 6% indicating genetic stability of all the fusants. Fusants growth were also observed on the media contained amino acid and antibiotics as required marked materials. DNA contents of the selected fusants were 1.6 to 2.7 times more than that of parent strains. With observation by TEM microscopy, spherical protoplasts were first released from the swollen parental cells and then contracted to fuse in the process of fusion. And fused cells were observed representative vesicle. Originally, the parental cells were observed as in the morphology of thick-walled and double membrane-surrounded rod shape with TEM microscopy.

• Korean Journal of Microbiology
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• v.28 no.1
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• pp.55-64
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• 1990

Cell volume and DNA contents of the fusants were similar to those of parents. Genetic stability of the fusants was increased when they were cultured on minimal medium (MM) rather than on complete medium (CM), and the fusants were stabilized by subculturing 7 generations each 7 day on MM agar. The finally selected fusants after being cultured for 6 months on CM were stable without segregation. The fusants could also form nuclein and ascospores, and show red and pink colors by the test of TTC colorization. Assimilability and fermentability of carbon sources of the fusants were similarto those of parents. The tolerance of KCl, NaCl, sodium propionate and cycloheximide showed the traits of one strain of parents. When the fusants were cultured for 72 hr and 60 hr in the medium containing 20% glucose and sucrose, respectively, the yield of ethanol for FWKS 260 was reached to 9.6 v/v% and 9.8v/v%, respectively. The sensitive strain Kyokai 7 was found to be killed entirely after cultivation of 48 hr by the killer toxin from the fusants. The recipient S 29 and Kyokai 7 were found to have neither L nor M dsRNA plasmid. However, K 52 and fusants had both L and M dsRNA plasmid of 4.7 kb and 2.5 kb, respectively. The curants treated by heat and cycloheximide did not contain M dsRNA plasmid, but had large amounts of L dsRNA plasmid of those of killer yeasts.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.1
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• pp.35-41
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• 2009

This study was conducted to investigate feasibility of feedstuff for animal using food waste by fermentation mechanism of indigenous microorganism. To achieve this purpose, indigenous bacteria was isolated from soils to use as an inoculant. Enzyme test was performed to verify activity of amylase, protease and lipase using isolated bacteria. Bacteria(H1, D1), which vigorously express the enzyme activity, was selected and used in the fermentation experiments of food waste. From the analysis of 16s rDNA sequencing, H1 and D1 were identified as Bacillus subtilis and Paenibacillus polymyxa, respectively. In the fermentation experiment, food waste was mixed with rice bran and popped rice to control moisture and nutrient content. Isolated bacteria(B. subtilis and P. polymyxa) was used as an inoculant. From the measured data such as temperature, pH and ORP, it can be verified that food waste adding the indigenous bacteria was effectively fermented. From the nutritional analysis of manufactured feedstuff, it showed that the contents of crude protein, crude fat and crude fiber were enough to use as feedstuff for animal. In addition, harmful components such as Pb, Hg, Cd, aflatoxin and salmonella concentration were not exceeded permitted standards. Therefore, fermented food waste using indigenous bacteria can be used as feedstuff.