• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.920-924
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• 2007

Two experiments were carried out on a laboratory scale. The first involved a study of the effect of green tea on characteristics of fermented juice of epiphytic lactic acid bacteria (FJLB). FJLB was treated with 50 g/L of green tea products as follows: new shoot powder (FJLB+N), leaf powder (FJLB+L), commercial powder (FJLB+P), sterilized new shoot powder (FJLB+SN), sterilized leaf powder (FJLB+SL) or sterilized commercial powder (FJLB+SP). FJLB without any additive was also prepared (Untreated FJLB). After incubation, the number of microorganisms in FJLB were studied. Subsequently, these FJLB were applied at 10 ml/kg to chopped rhodesgrass to study their effects on fermentation. Compared with untreated FJLB, the addition of green tea increased (p<0.05) lactic acid bacteria (LAB) and also aerobic bacteria counts in FJLB. At 60 d of ensiling, all the FJLB treated silages were well preserved, pH and butyric acid content were lower (p<0.001) and lactic acid was higher (p<0.001) than that of the control. Lactic acid content was significantly higher (p<0.001) with treated FJLB than with untreated FJLB. FJLB treated with sterilized green tea decreased (p<0.001) the pH and the lactic acid content was higher (p<0.001) than that in the unsterilized green tea silages.

• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.424-429
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• 2012

The intention of this research was to investigate the solubilization of primary sewage sludge using lactic acid bacteria cultured in a glucose and yeast extract medium. Glucose as the carbon source and yeast extract as the source of nitrogen were chosen as an economic medium with the potential for the mass production of lactic acid bacteria. The optimal concentrations of the medium were 3% (w/v) glucose and 2% (w/v) yeast extract. In this study, in order to improve field applications for the solubilization of sludge at sewage treatment plants, a powdered form of lactic acid bacteria was produced. The optimal inoculum of the powder for the maximum efficiency of solubilization was 1% (w/v). In that condition, the SCOD value increased from 8600 (mg/L) at the beginning of experiment to 10290 (mg/L) at 96 h, with the highest solubilization rate (20.6% DDCOD) and 11.2% (SCOD). Also, the TVFAs of the lactic acid bacteria inoculation group were produced more than that of the control group. In particular, acetic acid was produced 5 times more in the experimental group than in the control group. In this research, the potential of lactic acid bacteria in the pretreatment of primary sewage sludge as a solubilizer, and as an energy source producer for microbial fuel cells was revealed.

• Korean Journal of Microbiology
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• v.47 no.4
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• pp.308-315
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• 2011

The purpose of this work was to examine the antimicrobial activity derived from the lactic acid bacterium, UK-3 isolated from the vaginas of women of childbearing age. Various physiological and biochemical properties of this strain were characterized. Both the BIOLOG system and phylogenetic analysis using 16S rRNA sequencing were utilized for identification, and the strain was designated as Lactobacillus plantarum UK-3, and registered in GenBank as [JK266589]. Growth rate, production of organic acids (e.g., lactic acid and acetic acid), and pH during growth were monitored. The maximum concentrations of lactic acid and acetic acid were approximately 684.11 mM and 174.26 mM, respectively, and pH changed from 7.0 to 3.7 after 72 h of incubation. High performance liquid chromatography was used to confirm lactic acid and acetic acid production. Significant antimicrobial activity of the concentrated supernatant was demonstrated against various Gram-positive (e.g., Staphylococcus aureus, Staphylococcus epidermidis, Methicillin-resistant Staphylococcus aureus, Enterococcus faecalis, Neisseria species., Listeria monocytogenes), Gram-negative bacteria (e.g., Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis), and yeast (e.g., Candida albicans) by the plate diffusion method. As a result, the concentrated L. plantarum UK-3 cultures had lower acidity and inhibited the growth of all microorganisms tested, whereas the growth of L. acidophilus was not affected.

• Journal of Microbiology
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• v.42 no.4
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• pp.315-318
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• 2004

This study was undertaken to determine the suitability of tomato juice as a raw material for production of probiotic juice by four lactic acid bacteria (Latobacillus acidophilus LA39, Lactobacillus plantarum C3, Lactobacillus casei A4, and Lactobacillus delbrueckii D7). Tomato juice was inoculated with a 24­h-old culture and incubated at $30^{\circ}C$. Changes in pH, acidity, sugar content, and viable cell counts dur­ing fermentation under controlled conditions were measured. The lactic acid cultures reduced the pH to 4.1 or below and increased the acidity to $0.65\%$ or higher, and the viable cell counts (CFU) reached nearly 1.0 to $9.0\times10^9/ml$ after 72 h fermentation. The viable cell counts of the four lactic acid bacteria in the fermented tomato juice ranged from $10^6\;to\;10^8\;CFU/ml$ after 4 weeks of cold storage at $4^{\circ}C$. Pro­biotic tomato juice could serve as a health beverage for vegetarians or consumers who are allergic to dairy products.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.363-366
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• 2004

In order to obtain an industrial strain with higher L(+)-lactic acid yield, the wild type strain Rhizopus oryzae PW352 was mutated by means of Nitrogen ions implantation (l5 Kev, $7.8 \times 10^{14} - 2.08 \times 10^{15} ions/Cm^2$ and two mutants RE3303 and RF9052 were isolated. After 36 h shake-flask cultivation, the concentration of L(+)-lactic acid reached 131-136 g/l, the conversion rate of glucose was as high as 86%-90% and the productivity was 3.61 g/l.h. It was almost a 75% increase in lactic acid production compared with the wild type strain. Maximum fermentation temperature of RF9052 was increased to $45^{\circ}C$ from original $36^{\circ}C$. At the same time, the preferred range of fermentation temperature of RF9052 was broadened compared with PW352.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.681-685
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• 1992

Low molecular weight RNA(LMW RNA : 5S rRNA and tRNAs, <150 nucleotides) profiles of several bacteriocin production lactic acid bacteria from pig meats and reference lactic acid bacteria were generated on 10% denaturing polyacrylamide gel electrophoresis. Data evaluation including three molecular weight markers enabled the calculation of relative nucleotide units(RNU) for every band. Gels profiles and RNU evaluations were effective for identification of lactic acid bacteria species. LMW RNA profiles of lactic acid bacteria showed no variation in dependence on APT(All Purpose Tryptone Broth), TSB(Tryptic Soy Broth), MRS(Lactobacilli MRS Broth) different cultural medium.

• Quantitative Bio-Science
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• v.37 no.2
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• pp.125-132
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• 2018

In this study, noble strains of lactic acid bacteria were isolated and identified by genetic analysis of 16s rRNA. Also, pH-dependent growth curve, cholesterol assimilation ability and sugar production efficiency were measured. Lactic acid bacteria were identified to inhabit in the milks from various animals. Results of sequence analysis showed that there were differences in 16S rRNA sequence among strains and part of gene deletion was also recognized. Growth rates were varied, too, depending on the pH of the medium. Lactobacillus rhamnosus LOCK908 isolated from cow milk showed the highest growth rate and high cholesterol assimilation ability. Results of sugar fermentation tests were relatively consistent with the sequencing results. So, we propose newly isolated Lactobacillus rhamnosus LOCK908 as useful candidate for a starter of fermented beverage and probiotics. Results of this study will contribute to the isolation and identification of noble Lactic acid bacteria and to the public health.

• Journal of Dairy Science and Biotechnology
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• v.27 no.1
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• pp.45-51
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• 2009

$\gamma$-aminobutyric acid (GABA) is a ubiquitous nonprotein amino acid that is produced primarily by $\alpha$-decarboxylation of L-glutamic acid (Glu) catalyzed by the enzyme glutamate decarboxylase (GAD). It is well known as a neurotransmitter that regulates inhibitory neurotransmission in the mammalian central nervous system. In addition, GABA has been proved to be effective for lowering blood pressure in mammals. This paper is intended to provide basic information about GABA, including the functional and biological activity of GABA, GABA production by lactic acid bacteria, and the utilization of GABA in the production of dairy products.

• Journal of Wetlands Research
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• v.9 no.1
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• pp.123-131
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• 2007

Effect of nitrogen-load condition on hydrogen ($H_2$) production and bacterial community in a continuous anaerobic hydrogen fermentation were investigated. The slight $H_2$ production on extremely low nitrogen-load condition (C/N ratio: 180) at the start-up period. The highest $H_2$ production was obtained when the C/N ratio was 36, the $H_2$ production yield ($mol-H_2/mol-glucose$) reached to 1.7, and it was indicated that Clostridium pasteurianum mainly contributed to the $H_2$ production. The $H_2$ production was decreased on both the lower (C/N: 72) and higher (C/N: 18) nitrogen-load conditions. The excess nitrogen-load was not always suitable for the hydrogen production. The fluctuation of $H_2$ production seemed to be caused by a change in the bacterial community according to the nitrogen-load condition, while a recovery of $H_2$ productivity was possible by a control of nitrogen-load condition through the bacterial community change. When the nitrogen-load condition was not suitable for hydrogen production, the lactic acid concentration was increased and also lactic acid bacteria were definitely detected, which suggested that the competition between hydrogen fermentator and lactic acid producer was occurred. These results demonstrated that the nitrogen-load condition affect on the $H_2$ productivity through the change of bacterial community in anaerobic hydrogen fermentation.

• KSBB Journal
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• v.11 no.3
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• pp.380-387
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• 1996

The growth of recombinant E. coli and formation of the by-products were investigated. Glucose was consumed in approximately 8hours of cultivation when initial glucose concentration was 5g/1. When higher initial glucose concentrations were employed, it took approximately 16 to 20hours for the glucose to be consumed. When maltose or glucose was used as a carbon source, lactic acid and acetic acid were main by-products, while propionic acid and methanol production was not significant. Much by- products were formed at the higher initial carbon source concentrations. Higher concentration of lactic acid was observed when glucose was used, while higher concentration of acetic acid was observed when maltose was used. Lactic acid production affected the cell yield while acetic acid production affected the growth rate.