• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.4
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• pp.318-322
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• 2004

Lactic acid is an environmentally benign organic acid that could be used as a raw material for biodegradable plastics if it can be inexpensively produced by fermentation. Two genes (ldhL and ldhD) encoding the L-(+) and D-(-) lactate dehydrogenases (L-LDH and D-LDH) were cloned from Lactobacillus sp., RKY2, which is a lactic acid hyper-producing bacterium isolated from Kimchi. Open reading frames of ldhL for and ldhD for the L and D-LDH genes were 962 and 998 bp, respectively. Both the L(+)- and D(-)-LDH proteins showed the highest degree of homology with the L- and D-lactate dehydrogenase genes of Lactobacillus plantarum. The conserved residues in the catalytic activity and substrate binding of both LDHs were identified in both enzymes.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.5
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• pp.751-755
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• 2006

Dadih is Indonesian traditional fermented buffalo milk believed by the natives to have beneficial effects on human health. This may be due to the probiotic properties possessed by the lactic acid bacteria (LAB) involved in its fermentation process. It was discovered that ten strains of dadih lactic isolates possessed some probiotic properties in vitro. In this study, the adhesion properties of dadih LAB, in comparison with documented probiotic strains, were investigated in vitro by using mucin extracted from human faeces and Caco-2 cells as the models for human intestinal mucosal surface and intestinal cells respectively. The adhesion results showed the distinction of Lactobacillus reuteri IS-27560 in adhering to both mucus layer and Caco-2 cells. The competition assay for adhesion to the mucus layer between dadih LAB and selected pathogens indicated the competence of Lactococcus lactis IS-16183 and Lactobacillus rhamnosus IS-7257 in significantly inhibiting the adhesion of Escherichia coli O157:H7. Accordingly, these two strains may be potential candidates for use as probiotic strains. Overall, the adhesion properties of all dadih LAB strains were relatively comparable to that of Lactobacillus casei Shirota and Lactobacillus rhamnosus GG, the documented probiotic strains.

• Microbiology and Biotechnology Letters
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• v.24 no.6
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• pp.678-686
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• 1996

To improve the preservation of Kimchi, we isolated Lactobacillus plantarum lytic enzyme-producing strain from soil, and the enzyme was purified and characterized. From the observation of cultural and morpho- logical characteristics, the isolated strain was identified as Metarrisium anisopliae (Metschn.) Sorok. The enzyme was purified to 75-folds with 40% yields through affinity adsorption and CM-Sephadex C-50 column chromatog- raphy. The optimum pH and temperature for lytic activity are 4.0 and 40$\circ$C, respectively, and the enzyme acitvity is stable between pH 3.0 and 9.0, and up to 50$\circ$C. The enzyme is a monomeric protein with molecular weight of 40,000 daltons by SDS-PAGE and gel filtration. The enzyme is endopeptidase which breaks the peptide linkage of Lactobacillus plantarum peptidoglycan. The lytic action spectra confirmed that Leuconostoc mesenteroides, a useful strain for the fermentation of Kimchi, is not lysed by the enzyme. The enzyme activity is inhibited by N-bromosuccinimide (NBS), which probably indicates the involvement of tryptophan residue in active site of the enzyme, and also inhibited by Ag$^{+}$. The amino acid composition analysis showed that the enzyme contains more acidic amino acids than basic ones, and composition of alanine, glycine, proline and tyrosines was very high.

• The Korean Journal of Food And Nutrition
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• v.25 no.3
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• pp.629-636
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• 2012

Ginsenosides, ginseng saponin, are the principal components responsible for the pharmacological and biological activities of ginseng. In order to improve absorption and biological activities, the biotransformation of major ginsenoside to minor ginsenoside, as the more active compound, is required. In this study, we isolated Lactobacillus brevis THK-D57, which has high ${\beta}$-glycosidase activity, from Kimchi. The major ginsenoside Rb1 was converted to the minor ginsenoside 'compound K' during the fermentation of L. brevis THK-D57. The results propose that the biotransformation pathway to produce compound K is as follows: ginsenoside $Rb_1{\rightarrow}ginsenoside$ $Rd{\rightarrow}ginsenoside$ $F_2{\rightarrow}ginsenoside$ compound K.

• Food Science of Animal Resources
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• v.30 no.5
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• pp.795-803
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• 2010

A DF01 strain that inhibits tyramine-producing Lactobacillus curvatus KFRI 166 was isolated from Dongchimi, a traditional Korean fermented vegetable, and identified as Lactobacillus brevis by biochemical analysis and reverse transcriptase sequencing of 16S rRNA. The antimicrobial compound produced by L. brevis DF01 was secreted at a maximum level of 640 AU/mL in late exponential phase in MRS broth, and its activity remained constant during stationary phase. The activity of bacteriocin DF01 was totally inactivated by $\alpha$-chymotrypsin, pronase E, proteinase K, trypsin, and $\alpha$-amylase, but not by catalase, which indicates the compound was glycoprotein in nature. The activity was not affected by pH changes ranging from 2 to 12 or heat treatment (60, 80, and $100^{\circ}C$ for 30 min), but was reduced after autoclaving. Bacteriocin DF01 had bacteriolytic activity and a molecular weight of approximately 8.2 kDa, as shown by tricine-SDS-PAGE analysis. Therefore, bacteriocin DF01 can be used in the manufacture of fermented meat products due to its inhibition of tyramine-producing L. curvatus and non-inhibition of L. sake, which is used as a starter culture for meat fermentation.

• Journal of Microbiology and Biotechnology
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• v.1 no.2
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• pp.96-101
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• 1991

Phenotypic changes after plasmid curing experiment suggested that the bacteriocin production phenotype ($Bac^{+}$) might be linked to a chromosomal DNA and the mucin production phenotype ($Muc^{+}$) might be linked to a 62.5 kilobase (kb) plasmid (pMUC62) in Lactobacillus plantarum 27 isolated from meat starter culture. The non-mucoid ($Muc^{-}$) variants were missing pMUC62 but they produced bacteriocin as the wild strain ($Bac^{+}$). There was no difference in antibiotic resistance and sugar fermentation patterns between the wild strain ($Bac^{+}$ $Muc^{+}$) and the nonmucoid ($Bac^{+}$ $Muc^{-}$) variants. Antimicrobial spectrum of bacteriocin produced by both wild strain and $Muc^{-}$ variant of Lb. plantarum 27 included strains of Pediococcus acidilactici (A, M, H), Pediococcus sp. isolated from meat, Lactobacillus sp. isolated from meat, Lb. plantarum NCDO 955 and Staphylococcus aureus 485. Neither of the tested Gram negative bacteria were inhibited by bacteriocin. Antimicrobial activity of crude bacteriocin was retained after autoclaving, DNase or catalase treatment and exposure from pHs 4 to 9 but was lost after treating with several proteolytic enzymes and exposure at pH 10.

• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.201-210
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• 2019

Biotransformation of ginsenosides by microorganisms alters the absorption and bioavailability of ginseng as a medicinal herb. In this study, we isolated two kinds of fermenting microorganisms from Eoyukjang, which is a traditional Korean fermented food made from soybean. Next, we identified and detected their ability to convert major ginsenosides to compound K. The two microorganisms, referred to as R2-6 and R2-15, had 100% similarity with Lactobacillus plantarum subsp. plantarum ATCC $14917^T$ and Lactobacillus rhamnosus JCM $1136^T$, respectively. The optimal pH and growth temperature of the isolates were determined to be pH 6-7 and $30^{\circ}C$. After fermentation for 30 days, the major ginsenosides in the mountain-cultivated ginseng were transformed to the highly bioactive ginsenoside, compound K, in the final product.

• Microbiology and Biotechnology Letters
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• v.14 no.6
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• pp.487-493
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• 1986

Lactobacillus helveticus YM-1and Streptococcus lactis Ml$_3$ were inoculated together in reconstituted non-fat skim milk medium, and then their proteolytic activity and stimulatory compound for acid production were investigated. Significant difference between Lactobacillus helveticus YM-1 and Streptococcus lactis Ml$_3$was observed in the proteolytic activities. The proteolytic activity of Lactobacillus helveticus YM-1 and Streptococcus lactis Ml$_3$ was 105 $\mu\textrm{g}$/$m{\ell}$ and 30 $\mu\textrm{g}$/$m{\ell}$ when converted the amounts of hydrolysates of milk protein determined by Folin Ciocaleau phenol method into their tyrosine equivalent Stimulatory compounds in cell-free filtrate of Lactobacillus helveticus YM-1were identified as peptide with a molecular weight of approximately 4, 300 for the acid production by Streptococcus lactis Ml$_3$. Some kinds of amino acids, such as histidine, lysine, arginine and glutamic acid, were rich in acid hydrolysates of peptide. Among amino acids, histidine, glutamic acid and phenylalanine stimulated acid production, on the contrary isoleucine inhibited.

• Journal of Dairy Science and Biotechnology
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• v.33 no.1
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• pp.17-25
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• 2015

The present study was carried out to evaluate the preparation of the fermented milks with rice bran and to prove that the bacteria used are necessary for providing amino acids in this process. The rice bran on fermented milk with Streptococcus thermophilus (ST-body1) and Lactobacillus casei (LC-10). The fermentation limit was set until acidimetry score reaches 1. There are reports of titratable acidity, pH, viable cell count and amounts of organic acids affecting amino acid production about physical and chemical analysis measured using HPLC. Finally, sensory test was surveyed. In this study, the rate of acidification was higher in the fermented milk with rice bran than in the common fermented milk. In case of the number of cells was $1.0{\times}10^8CFU/mL$ in group. The lactic acid and citric acid content in yogurts prepared with rice bran using Streptococcus thermophilus (ST-body1) and Lactobacillus casei (LC-10) was higher than that in the control yogurt. Amino acids derived by rice bran were effected in fermentation for each bacteria's necessary amino acid production, and it made bacteria growth larger. From the physical test of the fermented milk with rice bran, flavor, texture, sweetness, overall taste of the fermented milk of Streptococcus thermophilus (ST-body1) were found to be much better than those of the other groups. The results obtained for the fermented milk prepared with rice bran using Streptococcus thermophilus (ST-body1) are significant.

• Korean Journal of Microbiology
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• v.50 no.1
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• pp.60-66
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• 2014

This study was carried out to investigate the characteristics of FOST (fermented omija sugar treatment extracts) using Lactobacillus brevis HLJ59. Antioxidant activities of FOST were evaluated through viable cell number of L. brevis HLJ59, DPPH radical scavenging activity, reducing power and SOD-like activity, compared to non-FOST(non-fermented omija sugar treatment extracts). Also it was to evaluate Angiotensin Converting Enzyme (ACE) and Urease inhibitory activity of FOST. The viable cell number of L. brevis was about $2.05{\pm}0.21{\times}10^8$, $6.31{\pm}0.56{\times}10^{11}$, and $8.14{\pm}0.14{\times}10^9$ at ${\times}2$, ${\times}5$, and ${\times}10$ dilution, respectively. DPPH radical scavenging activity of FOST was about 60.3%, 71.8%, and 44.5% at ${\times}2$, ${\times}5$, and ${\times}10$ dilution, respectively. The reducing power of FOST was about 0.92, 1.19, and 0.73 (OD at 700 nm) at ${\times}2$, ${\times}5$, and ${\times}10$ dilution, and SOD-like activity of FOST was about 50.4%, 53.7%, and 33.4% at ${\times}2$, ${\times}5$, and ${\times}10$ dilution, respectively. ACE and Urease inhibitory activity by FOST was about 47.4%, 78.2%, 56.4% and 58.1%, 83.4%, 63.2% at ${\times}2$, ${\times}5$, and ${\times}10$ dilution, respectively. The results indicated that the fermentation of omija sugar treatment extracts using Lactobacillus brevis HLJ59 increased the antioxidant activities campared to the non-fermented omija sugar treatment extracts.