• Journal of Life Science
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• v.22 no.9
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• pp.1194-1200
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• 2012

Lactic acid bacteria are generally recognized as beneficial probiotic organisms. Recent studies revealed that the potential of probiotic strains was essentially dependent on the bacterial-binding and adhesion capabilities to gut epithelial cells and the hydrophobicity of the cell surface. In this study, we screened some indigenous lactic acid bacteria from Kimchi and selected one lactic acid bacterium as a potential probiotic based on its cell surface hydrophobicity. Analysis of the 16S rRNA gene sequences of probiotic isolates indicated that the selected isolate (BCNU 9070 strain) was a member of Pediococcus pentosaceus. P. pentosaceus BCNU 9070 showed resistance to bile acids and acidic pH. The P. pentosaceus BCNU 9070 strain also inhibited the cell growth of six food-borne pathogens including Listeria monocytogenes and Shigella sonnei. In addition, the P. pentosaceus BCNU 9070 strain expressed bile salt hydrolase activity and showed an ability to assimilate cholesterol in vitro. On the basis of these results, P. pentosaceus BCNU 9070 is considered to have probiotic potential for applications in functional foodstuffs.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.325-331
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• 2012

The dual inoculation response of soybean with rhizobium and mycorrhiza was examined in pot vermiculite and field soils. In order to select a symbiotically compatible mycorrhiza with Bradyrhizobium japonicum, a highly germinating spore among 60 strains from 32 upland soils in southern part of Korea was obtained in Acaulospora sp., Gigaspora sp. and Glomus sp., respectively. As a result of dual inoculation of Glycin max cv. Dajangkong and Eunhakong both with $1{\times}10^8$cells of B. japonicum YCK 213 and 10 spores of each mycorrhiza in vermiculite pot, only Glomus sp. treatment together with the rhizobium showed significant increase ($P{\leqq}0.05$) both in shoot dry wt and nodule mass of not Eunhakong but Dajangkong. In red-yellow soils with pH 5.2($1:5H_2O$) and 203 mg of Lancaster P per kg of soil, in which $10^3$ cells of B. japonicum and $10{\pm}0.2$ spores of mycorrhizae per gram of soil were naturalized, grain yield of G. max cv. Dajangkong was increased to 3.9% by dual inoculation both of $4.8{\times}10^6$cells of B. japonicum and 10 spores of mycorrhizae per two seeds under condition applied with 30 kg $P_2O_5$ and 34 kg $K_2O$ per hectare compared to conventionally fertilized plot (2.75 MT $ha^{-1}$) added with 30 kg N $ha^{-1}$. However, there was not significant.

• Microbiology and Biotechnology Letters
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• v.27 no.6
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• pp.427-432
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• 1999

For the development of a multifunctional biocontrol agent, the siderophore-producing strain GL7 was isolated from a rhizosphere on chrome azurol S agar. The GL7 was identified as a strain of Pseudomonas fluorescents on the basis of their reactions to standard physicochemcial tests from Bergey's manual, API diagnostic test, and fatty acid analysis. P. fluorescents GL7 considerably inhibited spore germination and hyphal growth of phytopathogenic fungus Funsarium solani in a dual culture. In pot trials of bean with P. fluorescens GL7, the disease incidence was significantly reduced down to 5% from 70% of incidence in the untreated control. P. fluorescens GL7 also enhanced plant growth to nearly 1.5 times than that of the untreated control, promoting elongation and development of the roots. These results suggest that the plant growth-promoting P. fluorescens GL7 can play an important role in the biological control of soil-borne plant disease in a rhizosphere.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.214-222
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• 2008

This study was carried out to investigate the distribution characteristics, colonization patterns of arbuscular mycorrhizal fungi (AMF) at Ginseng- cultivated fields in Jeonnam province including Gokseong, Yeonggwang, Yeongam and Haenam area. Average density of AMF spores in all of analyzed areas was in the range of $3.4{\sim}5.9spores\;g^{-1}$ air-dried soil and spore density in the soil was increased gradually up to Ginseng cultivated fields grown for 3 years. However, AMF spore densities in the marginal field soil were $6.3{\sim}14.7spores\;g^{-1}$ air-dried soil and it was higher than those in Ginseng-cultivated field soils. A $45{\sim}106{\mu}m$ in diameter of AMF spores by size was dominant (74.3%) in Ginseng cultivated fields. AMF colonization association type in Ginseng roots was a Paris-type. Average rates of AMF infection ranged from 40% to 50%, while 64.4% of AMF infection occurred in Yeongam area. External hyphae length (EHL) in the rhizosphere soil of Ginseng cultivated field was in the range of $0.5{\sim}4.4m\;g^{-1}$ air-dried soil and the hyphae quantity was gradually increased proportional to increment of Ginseng cultivation years.

• Korean Journal of Microbiology
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• v.51 no.2
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• pp.169-176
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• 2015

The malolactic fermentation (MLF), which is widely used in winemaking, is the conversion of malic acid to lactic acid conducted by the malolactic enzyme (Mle) of lactic acid bacteria. In order to select the strains with MLF among 54 lactic acid bacteria isolated from the traditionally fermented foods, we designed a primer set that specifically targets the conserved regions of the mle gene and then selected four strains that harbor the mle gene of Lactobacillus plantarum. All strains were identified as L. plantarum by analyzing the 16S rRNA sequences, biochemical properties, and the PCR products of the recA gene. From comparison of the mle gene sequences consisting of 1,644 bp, the nucleotide and amino acid sequence of strain JBE60 correspond to 96.7% and 99.5% with those of other three strains, respectively. The strain JBE60 showed the highest resistant against 10% (v/v) ethanol among the strains. The strains lowered the concentration of malic acid to average 43%. Considering the ethanol resistance and conversion of malic acid, the strain JBE60 is considered as a potential starter for the malolactic fermentation.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.295-301
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• 2015

We investigated mycophagous ladybird, Illeis koebelei from 12 species of plants infected with powdery mildew in Gyeonggi-do, Korea. The pear tree, Pyrus ussuriensis var. macrostipes (Nakai), was most preferred by I. koebelei. This species was found from early July to early November in pear orchards. There was no entomophagous trace in the gut of I. koebelei without powdery mildew spores in a microscope. All stages except egg and pupa are obligate mycophagous, and the feeding potential is ranked as follows: fourth instar, adults, third instar, second instar, and first instar. Feeding amounts of each stage of I. koebelei were 45.6, 144.4, 372.2, 628.1, and $473.7mm^2$ of cucumber powdery mildew per day. Fourth instar larvae showed highest consumption of cucumber powdery mildew. Developmental periods of four larval instars and adults feeding cucumber powdery mildew were 1.2, 2.3, 2.3, 4.6, and 37.7 days, respectively, at $25^{\circ}C$. In this study, we could not determine the feeding potential of I. koebelei against the cucumber powdery mildew; therefore, and further studies are required to elucidate the potential of this species as a biological control agent, e.g., mass rearing, selection of low toxic chemical agents for Integrated Pest Management (IPM), and control techniques against powdery mildew in agro-ecosystems.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.429-444
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• 1998

Objective of this study was to select ectomycorrhizal fungi for black spruce(Picea mariana) inoculation to overcome the growth inhibitory effects of Kalmia angustifolia. Nineteen isolates representing 11 species of ectomycorrhizal fungi were tested for their abilities to grow and form mycorrhizae with black spruce seedlings in the presence of water leachate of leaves of Kalmia. Mycelium growth of 9 isolates were inhibited by the leaf leachate. Colony diameter and biomass of the other 10 isolates were either increased or unaffected under the same conditions. Acidic pH of the culture medium(pH 3 and 4) inhibited some of the fungi, but a combination of acidic pH and the leaf leachate was more inhibitory. Thirteen isolates were able to form ectomycorrhizae with black spruce in presence of 25% leaf leachate in pure culture. Four isolates, Paxillus involutus(NF4), Cenococcum geophilum(GB12), Laccaria laccata(GB23), and E-strain(GB45) formed mycorrhizae more successfully than the others in presence of up to 50% Kalmia leaf leachate. Black spruce seedlings pre-inoculated with these fungi were grown with Kalmia leaf leachate and live Kalmia plants during a four month greenhouse experiment. Abundant mycorrhizae(77-91% of root tips) were developed on seedlings pre-inoculated with P. involutus, L. laccata and E-strain but relatively poor mycorrhization(32% of root tips) resulted with C. geophidum. Over 90% of the short root mycorrhizae were attributed to the inoculated fungi although indigenous mycorrhizae also occurred on most seedlings. Persistence of the mycorrhizae was not affected by living Kalmia plants. Over 80% of the mycorrhizae on seedlings inoculated with P. involutus, L. laccata and E-strain and 53% of the mycorrhizae on seedlings inoculated with C. geophilum were attributable to the inoculant fungi. Control seedlings formed about 45% ectomycorrhizal short roots with indigenous fungi. The L. laccata and C. geophilum inoculated seedlings exhibited enhanced mycorrhizae formation in presence of Kalmia leaf leachate. Mycorrhizae formation with inoculant fungi was 4-15% lower at pH 4 than at pH 5, with the greatest inhibition occurring for L. laccata. Seedlings inoculated with P. involutus had the greatest shoot and root growth followed by L. laccata and E-strain inoculated seedlings. The P. involutus and L. laccata inoculated seedlings were significantly taller with more shoot dry biomass than the uninoculated(control) seedlings. E-strain inoculated seedlings had significantly higher shoot dry biomass and significantly lower number of first order lateral roots compared to the control but other growth parameters such as height, root dry weight and number of short root tips were not significantly different from the control. Seedlings inoculated with C. geophilum were not significantly different from the uninoculated seedlings in any of the growth parameters except for the number of first artier lateral roots which was significantly less than the control seedlings.

• Pediatric Infection and Vaccine
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• v.7 no.2
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• pp.211-217
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• 2000

Purpose : Salmonellosis including typhoid fever is still prevalent in Korea. Recently it has been reported that the incidence of salmonella gastroenteritis is increasing with a reduction of typhoid fever. We studied the clinical and laboratory features of salmonellosis. Methods : We evaluated the clinical records of 83 patients with salmonellosis who had been confirmed by stool culture from 1994 to 1999. Results : Annual incidence of salmonellosis showed an increasing tendency during recent 4 years. Seasonally, summer(45.8%) was the most prevalent, followed by fall(32.5%). Male to female ratio was 1.4 : 1. In age distribution, 64 cases(77.1%) were under 5 year-old, and 18 cases(21.7%) were younger than 1 year-old. Clinical features included diarrhea(96.4%), fever(91.6%), vomiting(49.4%), bloody stool(42.1%), abdominal pain(40.1%) and tenesmus(12.0%). In serogroups, there was no group A and group B, group C, group D(including 2 cases of S.typhi) and group E were in 41.0%(34 cases), 3.6%(3 csaes), 51.8%(43cases) and 3.6%(3 cases), respectively. In Widal test, 5 cases(13.5%) and 1 case(2.7%) of group B, C and E(total 37 cases) were observed the O titer above 1 : 80 and 1 : 320, respectively. However, in 36 cases of group D, 19 cases(52.7%) and 9 cases(25.0%) were above the O titer 1 : 80 and 1 : 320, respectively. Antibiotics resistant rates to ampicillin, trimethoprim/sulfamethoxazole and chloramphenicol were 23.2%, 10.1% and 51.4%, respectively. Conclusion : Salmonellosis has become a common cause of gastroenteritis in children, especially under the pre-school age. Isolation of salmonella is neccessary for accurate diagnosis of gastroenteritis and typhoid fever. A careful attention of the use of antibiotics is needed to reduce the muilti-drug resistant strains.

• Food Science of Animal Resources
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• v.29 no.2
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• pp.168-177
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• 2009

This study was conducted to investigate the dietary effects of locally grown herbs (Mentha piperascens, PM; Rubus coreanus, RC; Tagetes patula, MG) on the growth performance and meat quality of broiler chicken. A total of 600 1-d-old Ross male broiler chicks were divided into eight groups and were fed control diets (antibiotics-medicated or non-medicated commercial diets) or experimental diets (non-medicated diets containing 0.3 or 0.5% PM, 0.3 or 0.5% RC, or 0.3 or 0.5% MG) for 5wk. The body weight gains and feed conversion rates (FCRs) in all the groups that were fed diets containing PM, RC, or MG were significantly improved compared to those in the non-medicated control group (p<0.05). The relative weights of various organs, the serum cholesterol levels, and the GOT/GPT activities in all the groups were also not significantly different. The superoxide dismutase (SOD)-like activities in the groups that were fed diets containing 0.3% PM or 0.3% MG were significantly increased compared to those in the non-medicated control group (p<0.05). The number of cecal lactic-acid bacteria in the groups that were fed diets containing 0.3% PM or 0.5% RC tended to increase. The malondialdehyde contents in the leg muscles were significantly lowered by feeding with PM or MG (p<0.05). The physicochemical properties of the edible meat, including the shear force, water-holding capacity, heat loss, pH, and muscle color degrees $(CIEL^*.\;a^*.\;b^*)$, were not affected by the dietary treatments. It has been suggested that spontaneous Korean plants promote the growth of broilers and may delay lipid oxidation in edible muscles without any negative effect when added in broiler diets.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.456-464
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• 2014

Kimchi was prepared with three types of salt (4-year-aged solar salt, FS; 1-year-aged solar salt, OS; and purified salt, PS), using Leuconostoc citreum GJ7 as the starter culture. The prepared kimchi was fermented (up to 0.5-0.6% of acidity) and stored for 5 months at $-1^{\circ}C$. During the storage period, the acidity of FS kimchi increased gradually, whereas that of PS kimchi increased sharply. The yellowness (b) color value of PS kimchi (63.4) was higher than that of other kimchis with solar salts (55.6-60.3). Hardness of FS kimchi (1,912.6 gf) was greater than that of the other kimchis (1,554.4-1,650.2 gf) during the storage period. Moreover, sensory evaluation showed higher scores for FS kimchi than for other kimchis. These results suggest that FS is more suitable salt than PS for long-term storage of kimchi.