ABSTRACT
BACKGROUND: Panax ginseng is a physiologically active plant widely used in traditional medicine that is characterized by the presence of ginsenosides. Rb1, a major ginsenoside, is used as the starting material for producing ginsenoside derivatives with enhanced pharmaceutical potentials through chemical, enzymatic, or microbial transformation. METHODS: To investigate the bioconversion of ginsenoside Rb1, we prepared kimchi originated bacterial strains Leuconostoc mensenteroides WiKim19, Pediococcus pentosaceus WiKim20, Lactobacillus brevis WiKim47, Leuconostoc lactis WiKim48, and Lactobacillus sakei WiKim49 and analyzed bioconversion products using LC-MS/MS mass spectrometer. RESULTS: L. mesenteroides WiKim19 and Pediococcus pentosaceus WiKim20 converted ginsenoside Rb1 into the ginsenoside Rg3 approximately five times more than Lactobacillus brevis WiKim47, Leuconostoc lactis WiKim48, and Lactobacillus sakei WiKim49. L mesenteroides WIKim19 showed positive correlation with ß-glucosidase activity and higher transformation ability of ginsenoside Rb1 into Rg3 than the other strains whereas, P. pentosaceus WiKim20 showed an elevated production of Rb3 even with lack of ß-glucosidase activity but have the highest acidity among the five lactic acid bacteria (LAB). CONCLUSION: Ginsenoside Rg5 concentration of five LABs have ranged from â¼2.6 µg/mL to 6.5 µg/mL and increased in accordance with the incubation periods. Our results indicate that the enzymatic activity along with acidic condition contribute to the production of minor ginsenoside from lactic acid bacteria.
ABSTRACT
Rapid colorimetric methods using various indicator reagents have been developed to monitor bacterial viability. Here, we examined the applicability of a method based on the reduction of resazurin or water-soluble tetrazolium salt-8 (WST-8) to screen lactic acid bacteria (LAB) for growth, tolerance against bile acid and low pH. The resazurin reduction test proved unsuitable for screening LAB such as Lactobacillus plantarum and Leuconostoc mesenteroides since it reacted with acid present in the cultures. LAB growth could be indirectly quantified by measuring WST-8 reduction. This method proved more sensitive and quickly results than counting bacterial colony forming units and turbidity at 600 nm in the presence of bile and acid. Our results suggested that the WST-8-based method could be useful for the characterization of growth and tolerance of the lactic acid producing bacteria.
Subject(s)
Colorimetry/methods , Lactobacillales/growth & development , Lactobacillales/physiology , Probiotics/metabolism , Bile Acids and Salts/metabolism , Colony Count, Microbial , Lactobacillales/isolation & purification , Lactobacillales/metabolism , Lactobacillus plantarum/isolation & purification , Lactobacillus plantarum/metabolism , Microbial Viability , Oxazines/metabolism , Oxidation-Reduction , Probiotics/isolation & purification , Sensitivity and Specificity , Tetrazolium Salts/metabolism , Xanthenes/metabolismABSTRACT
We report the draft genome sequence of Lactobacillus sakei strain wikim 22, a Lactobacillus species isolated from kimchi in North Chungcheong Province, South Korea, having 155 contigs with 2,447 genes and an average G+C content of 40.61%.
ABSTRACT
This report describes the draft genome sequence of Lactobacillus plantarum strain wikim18, isolated from the traditional Korean food kimchi. The reads generated by Ion Torrent PGM were assembled into 327 contigs. RAST annotation of the genome revealed 12 tRNAs and 3,316 protein-coding gene sequences.