• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.344-356
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• 2005

There are normal inhabitants doing medically useful functions in the body. There are many kinds of bacteria performing specific functions in the oral cavity. Two strains of lactic acid bacteria were isolated from inhabitants of caries-free children's oral cavity, which inhibited the formation of artificial plaque by Streptococcus mutans and the production of volatile sulfur compounds by anaerobic bacteria. The isolates were identified by the test using API 50 CHL medium kit and 16S rDNA partial sequencing. 1. Two isolates were Gram-positive bacilli and produced hydrogen peroxide. 2. When Streptococcus mutans was cultured in the media, the mean weight of formed artificial plaque on the orthodontic wires was $124.4{\pm}30.4\;mg$, whereas being reduced to $5.2{\pm}2.0mg$ and $10.6{\pm}6.6mg$ in the media cultured with Streptococcus mutans and each isolate, respectively (p<0.05) 3. The number of viable cells of Streptococcus mutans was $3.4{\times}10^9$ per ml in the cultured solution, whereas those of Streptococcus mutans in the combined culture with each of isolates were $4.6{\times}10^8\;and\;2.4{\times}10^8$ per ml. 4. The optical density was 1.286 in the supernatant of Fusobacterium nucleatum after vortexing for 30minutes, whereas in the supernatant of combined Fusobacterium nucleatum and each isolate, they were reduced to 0.628 and 0.497, which the percentages of coaggregation between them were 29.4% and 57.8%, respectively 5. The optical density of Fusobacterium nucleatum precipitate was 1.794 in the culture media containing cysteine and $FeSO_4$, being reduced to 1.144 and 0.915 in the coaggregated precipitates of Fusobacterium nucleatum and each isolate. The optical density of Porphyromonas gingivalis precipitate was 1.932 in the culture media, being reduced to 1.170 and 1.266 in the coaggregated precipitates of Porphyromonas gingivalis and each isolate. 6. When two isolates were tested with API 50 CHL medium kit, those were identified Lactobaciallius salivarius and Lactobaciallius delbrueckii subsp. lactis. 7. The similarity values of 16S rDNA sequence between each of isolates and Lactobaciallius salivarius subsp. salicinius were 99.60% and 99.73%, respectively, meaning that isolates were Lactobaciallius salivarius subsp. salicinius. These results indicated that two strains isolated from caries-free children's saliva, which inhibited the formation of artificial plaque and the production of volatile sulfur compounds, were identified as Lactobaciallius salivarius subsp. salicinius.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.317-325
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• 1988

The effects of various heat treatments of soy milk prepared from soy protein concentrate on growth and acid production by five species of lactic acid bacteria were investigated. Sensory property and sedimentation characteristics of soy yogurt prepared from heat-treated soy milk were also evaluated. Heat treatment of soy milk stimulated acid production by all cultures. Acid production was generally proportional to degree of heat treatment and acid production by all cultures except Streptococcus lactis was maximum in soy milk heated at $121^{\circ}C-1min$. However, viable cell count was not changed markedly by heat treatment of soy milk. Sensory property of soy yogurt beverage (SYB) prepared from soy milk heated at $95^{\circ}C-30min$ was better than that of unheated sample while sensory property of SYB prepared from soy milk heated at $121^{\circ}C-15min$ was inferior to that of unheated sample. Heat treatment of soy milk generally retarded sedimentation of curd in SYB.

• Food Science of Animal Resources
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• v.35 no.4
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• pp.541-550
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• 2015

The purpose of this study was to investigate the effect of lactic acid bacteria (LAB) cell wall extract on the proliferation and cytokine production of immune cells to select suitable probiotics for space food. Ten strains of LAB (Lactobacillus bulgaricus, L. paracasei, L. casei, L. acidophilus, L. plantarum, L. delbruekii, Lactococcus lactis, Streptococcus thermophilus, Bifidobacterium breve, and Pedicoccus pentosaceus) were sub-cultured and further cultured for 3 d to reach 7-10 Log colony-forming units (CFU)/mL prior to cell wall extractions. All LAB cell wall extracts failed to inhibit the proliferation of BALB/c mouse splenocytes or mesenteric lymphocytes. Most LAB cell wall extracts except those of L. plantarum and L. delbrueckii induced the proliferation of both immune cells at tested concentrations. In addition, the production of T_H1 cytokine (IFN-γ) rather than that of T_H2 cytokine (IL-4) was enhanced by LAB cell wall extracts. Of ten LAB extracts, four (from L. acidophilus, L. bulgaricus, L. casei, and S. thermophiles) promoted both cell proliferating and T_H1 cytokine production. These results suggested that these LAB could be used as probiotics to maintain immunity and homeostasis for astronauts in extreme space environment and for general people in normal life.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.770-776
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• 1995

For the purpose of development of non-toxic and biodegradable flocculant, chitosan complex was isolated from Ganoderma lucidum wastes. The isolated complex was identified as the expected chitosan-glucan complex by IR specta. The complex was extracted by treatment of 50% NaOH solution at 120$\circ$C for 5 hrs, namely optimal condition and solubilized with 2% acetic acid for fur-ther use as flocculant. Preliminary experiments showed that the solubilized complex had higher flocculation activity of 1.3 fold than commercial chitosan at 400 mg/l concentration in soybean curd wastewater. Also the solubilized complex removed 83% of MLSS and 60% of COD in the soybean curd wastewater treated by photosynthetic bacteria, 50% of turbidity and 21% of MLSS in sugar industry wastewater, and 90% of turbidity and 89% of MLSS in alcohol fermentation wastewater. Bacterial cell flocculation activities of the solubilized chitosan-glucan complex were 89% in Bacillus subtilis broth, 81% in Streptococcus lactis broth, and more than 90% in Escherichia coli broth after standing for 2 days. The results reveal that chitosan-glucan complex from Ganoderma lucidum wastes can substitute for commercial chitosan as non-toxic and biodegradable flocculant.

• Biomolecules & Therapeutics
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• v.9 no.2
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• pp.79-87
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• 2001

Heat shock proteins serve as chaperone by preventing the aggregation of denatured proteins and promote survival of pathogens in harsh environments. In this study, heat shock gene encoding a 84-kDa (p84) protein, which is one of the three major heat shock proteins in S. pneumoniae, was cloned and characterized. PCR with a forward primer derived from N-terminal amino acid sequence of the p84 and a reverse primer derived from the conserved second ATP-binding region of Clp family was used for amplification of the gene encoding the p84 and subsequently the PCR product was used for sequence determination. Sequence analysis of the p84 gene demonstrated that it is a member of ClpL. The deduced amino acid sequence of pneumococcal ClpL shows homology with other members of the Clp family, and particularly, even in variable leader region, with bovine Clp-like protein and L. lactis ClpL. S. pneumoniae clpL is the smallest clop member (701 amono acids) containing the two conserved ATP-binding regions, and hydrophilic N-terminal variable region of pneu-mococcal Clp ATPase is much shorter than any known Clp ATPases. Histidine tagged ClpL was overexpressed and purified from E. coli. Immunoblot analysis employing antisera raised against pneumococcus p84 demonstrated no cross-reactivity with Clp analog in Eschericha coli, Staphylococcus aureus and human HeLa cells. Preimmunization of mice with ClpL extended mice life partially but did not protect them from death.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.522-530
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• 2007

This experiment was carried out to measure the content of lactoferrin, IgA, $IgG_1,\;IgG_2$, in Holstein colostrum, and to test the effect of it's colostrum on the antibacterial activity to pathogenic bacteria and the growth stimulation of lactic acid bacteria. Colostrum was collected at the first, second, and third day after parturition in summer and winter season. The levels of lactoferrin, IgA, $IgG_1,\;and\;IgG_2$ in Holstein cow colostrum were 0.30 mg/mL, 0.37 mg/mL, 4.00 mg/mL, 0.37 mg/mL, respectively, on the first day of the summer season whereas they were 1.16 mg/mL, 2.60 mg/mL, 13.35 mg/mL, 1.30 mg/mL on the first day of the winter season, postpartum. Heat treated ($65^{\circ}C$ for 30 min) or non-treated colostrum showed antibacterial activity toward Escherichia coli. The growth of commercial mixed strains (Bifidobacterium longum, Lactobacillus acidophilus, Streptococcus themophilus), L. acidophilus, L. casei, L. bulgaricus, and L. lactis subsp. cremoris were improved in first, second and third day colostrum compared to normal milk. Commercial miked strains (B. longum, L. acidophilus S. themophilus) lowered the pH to 4.97-5.22 and 4.89 while increasing the titratable acidity to 0.75-0.88% and 0.70% in colostrum and normal milk, respectively. However, L. casei, L. bulgaricus, L. lactis subsp. cremoris lowered the pH to 5.96-6.47 and 6.5-6.8 while increasing the titratable acidity to 0.29-0.48% and 0.20-0.25% in colostrum and normal milk, respectively.

• Food Science of Animal Resources
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• v.23 no.3
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• pp.269-277
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• 2003

This study was carried out to evaluate the safety of Korean human milk. The microorganisms were identified from human milk of 149 healthy mothers by two collection methods, hand and pump expression. The means of total bacterial counts were 2.33x10$^4$ cfu/mL on the samples collected by the pump expression and 7.83xl0$^3$ cfu/mL on those collected by the hand expression. Therefore, the total bacterial counts of pump expression samples was 9.80xl0$^2$∼3.06x10$^4$ cfu/mL more than that of hand expression samples. The coliform counts of pump expression was 9.36xl0$^3$∼8.57xl0$^4$ cfu/mL more than that of hand expression. However, there was any significant differences of the lactic acid bacterial counts between the two samples collected by each methods. 100 strains of 5 patterns of total bacterial counts were isolated based on the morphology of colony in the standard plate count agar. 13 species were identified among the isolated strains. The dominant species in Korean human milk were Staphylococcus which 7 subspecies identified(81% in the rate of total bacteria, 1.07x10$^4$ cfu/mL). Other species identified were Micrococcus, Bacillus, Providencia, Pseudomonas, Yersinia and Acinetobacter. 36 strains of 6 patterns of lactic acid bacterial counts were isolated based on morphology of colony in the BCP agar. 7 species were identified among the isolated strains. The dominant species of lactic acid bacteria in Korean human milk were Lactobacillus brevis(50.9% in the rate of lactic acid bacteria, 4.72xl0$^4$ cfu/mL). Others species identified(49.1% lactic acid bacteria) were Lactobacillus curvatus, Lactobacillus delbrueckii subsp. lactis, Lactobacillus acidophilus, Leuconostic lactis and Streptococcus salivarius subsp. thermophilus.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.1
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• pp.63-68
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• 1986

In order to examine related bacteria on the maturation of cured loin ham, bacteria isolated during curing periods from ham, which counted coliform group, psychrotrophic and halo-tolerant bacteria. The results are as follows; The isolated bacteria from ham during the curing period were Staphylococcus spp. 24 strains, Bacillus spp. 21 strains, Lactobacillus spp. 10 strains, Coryneform 2 strains. Microbacterium spp. 2 strains and Gram negative rods 8 strains. Micrococcus spp. were identified M. varians 12 strains and M. luteus 3 strains, and Streptococcus spp. identified S. faecium 14 strains, S. lactis 2 strains. Lactobacillus spp. were isolated L. Plantarum 4 strains, L. brevis and L. casei 1 strains. In the case of cured ham, the number of coliform group and psychrotrophic bacteria were decreased but halo-tolerant bacteria were increased for 10 days of curing period. On the brine solution. the number of coliform group, psychrotrophic and halo-tolerant bacteria were increased for 10 days. 4 days and 20 days, respectively.

• Journal of Dairy Science and Biotechnology
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• v.17 no.1
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• pp.1-10
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• 1999

A bacteriocin produced by Lab. acidophilus GP4A isolated from fecal contents of pig was characterized. Lab. acidophilus GP4A produced a heat-stable and pH-resistant bacteriocin, which was hydrolyzed by trypsin and pepsin and active against various microorganisms. Lab. acidophilus GP4A produced bacteriocin at maximum rate when grown in MRS broth(pH 6.5${\sim}$7.5) at$37^{\cric}C$ or $40^{\cric}C$. The bacteriocin produced by Lab. acidophilus GP4A inhibited the growth of Lactobacillus delbrueckii subsp. lactis 4794 in early logarithmic phase. The bacteriocin was purified by ammonium sulfate precipitation and Octyl sepharose CL-4B column chromatography. The purification resulted in a final yield of 21.7% and a 13.6-fold increase in the specific activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.787-794
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• 2009

In this study, a new method for extending storage-life and palatability of Betula platyphylla sap by applying lactic acid bacteria fermentation was developed. The fluids of saps were filtered through 0.22 ${\mu}m$ membrane filter and each fermented by 8 different lactic acid bacteria which are Lactobacillus acidophilus, Lactobacillus brevis, Leuconostoc mesenteroides, Leuconostoc lactis, Lactococcus lactis, Pediocossus pentosaceus, Pediococcus dextrinicus, Streptococcus thermophilus. All the tested lactic acid bacteria except P. dextrinicus grew fast up to $10^6{\sim}10^7cfu/mL$ levels and lowered pH down to about pH 4 levels in 48 hours in both saps. The produced organic acids and lowered pH level inhibited the growth of spoilage microorganisms almost completely for 2 weeks during storage at room temperature. Addition of xylitol in the saps before fermentation accelerated the growth of lactic acid bacteria and increased the sweetness and overall taste of final product. The filtration process did not affect the mineral compositions of Betula platyphylla saps. Also the compositions and amounts of minerals showed very minor differences before and after fermentation in Betula platyphylla saps inoculated with L. acidophilus. By applying lactic acid fermentation to extend storage-life of tree saps instead of heat treatment, it was possible to keep natural minerals in active forms without any modifications.