• Microbiology and Biotechnology Letters
• /
• v.39 no.4
• /
• pp.390-396
• /
• 2011

Lactobacillus sakei is known to be the most populous lactic acid bacteria in over-ripened kimchi. Twenty three strains of Leuconostoc species inhibiting the growth of Lb. sakei were isolated from kimchi and amongst these the Leuconostoc mesenteroides strain CK0122 exhibited the highest antagonistic activity against Lb. sakei. The culture supernatant of the strain CK0122 was fractionated by a molecular weight cutter and lyophilized. The fraction with a molecular weight of less than 3,000 Da showed antagonistic activity against Lb. sakei. The antibacterial activity of the active fraction was sensitive to proteinase K treatment, confirming its proteinaceous nature (bacteriocin). The crude bacteriocin was active in the pH range of 4 to 7 and extremely stable after 15 min of heat treatment at $121^{\circ}C$. The crude bacteriocin inhibited the growth of Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Alcaligenes xylosoxydans, Flavobacterium sp., and Salmonella typhimurium.

• Korean Journal of Food Science and Technology
• /
• v.34 no.6
• /
• pp.1085-1090
• /
• 2002

Leuconostoc mesenteroides, the major bacterium in the initial phase of lactate-fermentation in kimchi, produces lactic acid, acetic acid, mannitol, and $CO_2$. It also secrets dextransucrase, which catalyzes the transfer reaction of glucose from sucrose to maltose, synthesizing mainly panose ($6^_2-{\alpha}-D-glucopyranosylmaltose)$, a probiotic oligosaccharide. To use the strain as a starer culture to produce high amount of panose during kimchi fermentation, we screened psychrotrophic strains showing fast growth rate at low temperature among the isolates of Leuconostoc sp. and selected two strains showing high dextransucrase activity. The strains were identified as Leuconostoc mesenteroides, which can be used as function added-starters for lactate-fermented foods.

• Journal of Microbiology and Biotechnology
• /
• v.9 no.2
• /
• pp.219-222
• /
• 1999

A simple sequence of membrane concentration and DEAE-Cellulose chromatography has been optimized to give a purified dextransucrase from Leuconostoc mesenteroides B-512FMCM with the highest specific activity (248.8 IU/mg protein) ever reported in high yield (overall 88.7%) for dextransucrase. When there was no sucrose in the dextransucrase and the dextran reaction digest, the dextransucrase hydrolyzed glucose from dextran. The glucose was transferred to the other glucoses from dextran and formed isomaltose and isomaltodextrin. The transglycosylation efficiency of glucose from dextran was much higher with acceptors. The dextransucrase can be used for the production of various kinds (or structures) of oligosaccharides using dextran and various acceptors with almost 100% theoretical yield.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.29 no.5
• /
• pp.802-806
• /
• 2000

The transglycosylation reaction by dextansucrase from Leuconostoc mesenteroides B512FMC/6HG8 was investigate with cellobiose as an acceptor molecule and sucrose as a donor. he optimal conditions of transglycosylation on cellobiose were found that the ration of sucrose to cellobiose was 3:1, the amount of enzyme was 2U/mL, the ionic strength of buffer was 25 mM, pH was 5.0 and reaction temperature was $25^{\circ}C$. also, acceptor products of cellobiose by transglycosylation were a series of oligosaccharides showing the degree of plymenzation of 6.

• Journal of Applied Biological Chemistry
• /
• v.52 no.1
• /
• pp.33-37
• /
• 2009

A saccharified-rice was fermented using Leuconostoc(Ln.) mesenteroides KC51 strain in various dry matter (DM) contents (4%, 8%, and 12%) at $30^{\circ}C$ for 18 h. The changes of viable cell number, acid production and phytate degradation in saccharified-rice during fermentation were investigated. The viable cell population of Ln. mesenteroides KC51 was increased rapidly in proportion to DM contents during the 9 h of cultivation. The changes of pH and titratable acidity in saccharified-rice were dependent on DM contents. At high DM content (12%), the viable cell number of Ln. mesenteroides KC51 increased to 9.56 log CFU/g after 6 h of fermentation. The pH and titratable acidity reached to pH 3.38 and 0.93% after 18 h of fermentation, respectively. The phytate, known as an antinutrient factor, in saccharified-rice was degraded by Ln. mesenteroides KC51 cultivation. The decrease of phytate during fermentation approximately coincided with the increase of Ln. mesenteroides KC51 population observed in fermented saccharified-rice. Regardless of DM contents, the levels of phytate were reduced to around 50% of initial concentration.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.5
• /
• pp.660-665
• /
• 2008

The aim of this work was to investigate the microbiological and physicochemical properties of the rice sourdough for Jeungpyun prepared by mixed culture of Saccharomyces cerevisiae (S. cerevisiae) and Leuconostoc mesenteroides (L. mesenteroides) strains. The rice sourdough was fermented with S. cerevisiae and L. mesenteroides strains in rice dough for 24 hours at $30^{\circ}C$. Growth of L. mesenteroides strain was decreased after inoculation, however, it increased again after 18 hours of dough fermentation, and the growth of S. cerevisiae showed a typical growth pattern. Also, total aerobic microorganisms counts in rice sourdough were decreased due to the produced organic acids and ethanol during dough fermentation. These products led to a favorable fermentative quotient (FQ; molar ratio between lactic to acetic acid) value of $1.9{\sim}3.2$ and more stable fermentation for rice sourdough formation. The expansion ratio and viscosity were considerably increased by mixed cultivation of S. cerevisiae and L. mesenteroides strains. Addition of the brown rice at 10% (w/w) to dough preparation increased the relative expansion ratio to the highest value.

• Microbiology and Biotechnology Letters
• /
• v.48 no.4
• /
• pp.455-462
• /
• 2020

Leuconostoc mesenteroides CJNU 0705 was isolated from a breast milk sample and identified by 16S rRNA gene sequencing and confirmed by its ability to produce dextran from tryptic soy agar plates supplemented with 2% sucrose. This strain can absorb various heavy metals including lead (Pb) and cadmium (Cd) which are both found in fine dust and have been shown to be harmful to human skin. In addition, Leu. mesenteroides CJNU 0705 has demonstrated antimicrobial activity against Propionibacterium acnes, the primary causative agent of acne. Given these traits it was natural to evaluate the use of this strain in the fermentation of several natural extracts from green tea, carrot, annual wormwood, parsley, broccoli, and corn silk, which are known to improve skin health, to see if it could increase their dextran content when supplemented with no sucrose, 2% sucrose, or 2% sucrose and 3% yeast extract. The extracts supplemented with both yeast and sucrose were found to produce the most dextran, which was confirmed by the scanning electron microscope (SEM) images. These results suggest that Leu. mesenteroides CJNU 0705 and its fermented natural extracts could be used as functional materials for improving human skin health.

• Journal of Applied Biological Chemistry
• /
• v.54 no.1
• /
• pp.21-25
• /
• 2011

A lactic acid bacterial strain showing high acid production in saccharified-rice suspension was isolated from Kimchi. This strain was analyzed by API 50 CHL kit and 16S rRNA sequencing analysis and identified as Leuconostoc mesenteroides 310-12. Saccharified-rice suspension was fermented using L. mesenteroides 310-12 strain at $30^{\circ}C$ for 15 h. The changes of pH, titratable acidity and viable cell number during fermentation were determined. The pH and titratable acidity were reached to pH 3.57 and 0.40% after 15 h fermentation, respectively. The viable cell population of L. mesenteroides 310-12 was rapidly increased to $8.9{\times}10^8$ CFU/g during the 15 h of cultivation. The contents of lactic acid and acetic acid were determined to be 0.077% and 0.065% after 15 h fermentation, respectively. The rice-based fermented beverage was manufactured by blending L. mesenteroides 310-12 fermented broth and some food additives. When this beverage was stored at $4^{\circ}C$, the viable cells population was decreased to $1.0{\times}10^7$ CFU/g and pH was nearly maintained for 25 days.

• KSBB Journal
• /
• v.19 no.5
• /
• pp.363-367
• /
• 2004

Leuconostoc mesenteroides NRRL B-1149 produces various glucoseyltransferases for the synthesis of dextran, levan and glucose-1-phosphate using sucrose as a substrate. A sucrose phosphorylase (1149SPase) was purified from L. mesenteroides NRRL B-1149 culture by using hollow fiber filtration (30 kDa cut off), Toyopearl DEAE 650 M column chromatography and following two times of DEAE-Sepharose column chromatographies. The specific activity of the purified 1149SPase was 25.7 (U/mg) with $16\%$ yield. The 1149SPase showed a molecular size of 56 kDa on denatured $10\%$ SDS-PAGE. The N-terminal amino acid sequence of the enzyme was MEIQNKAM. The optimum pH and temperature of this enzyme were 6.2~6.5 and 37^{circ}C, respectively. It had an apparent K_{m} of 6.0 mM and K_{cat} of 1.62/s for sucrose. 1149SPase crystal was formed by hanging drop diffusion technique using 20 mM calcium chloride dihydrate, 100 mM sodium acetate trihydrate pH 4.6 and $30\%$ 2-methyl-2,4-pentanediol as vaporizing and reservation solution. The 1149SPase catalyzes transferring of glucose from isomaltose or sucrose to salicin and salicyl alcohol by disproportionation reaction or acceptor reaction and synthesized two acceptor products, respectively.

• Journal of Microbiology and Biotechnology
• /
• v.4 no.4
• /
• pp.305-315
• /
• 1994

Nineteen strains of bacteriocin-producing lactic acid bacteria were isolated from 432 Kimchi samples, and identified by the comprehensive biochemical and morphological tests verifying their cellular fatty acid composition. Using partially purified bacteriocins from these isolates, their inhibitory activities against other lactic acid bacteria and some pathogens, and sensitivity to enzyme and heat treatments were tested. The isolates were identified as Lactobacillus plantarum (2 strains), L curvatus (2 starins), L brevis (2 strains), Enterococcus faecium (6 strains), Leuconostoc mesenteroides subsp. mesenteroides (1 strain) and Lactobacillus sp. (6 strains). The bacteriocins produced by E. faecium strains provided the broadest spectrum of inhibition, affecting against other Gram-positive bacteria including lactic acid bacteria and health-threatening bacteria such as Clostridium perfringens and Listeria monocytogenes. The bacteriocins of Lactobacillus sp., L plantarum and L brevis strains were capable of inhibiting many strains of the lactic acid bacteria, whereas those of L curvatus and L mesenteroides subsp. mesenteroides strains were only inhibitory to a few strains. Generally, the inhibitory activities of both E. faecium and Lactobacillus sp. strains were greater than those of other producer strains. The bacteriocins from the isolates were sensitive to several proteolytic enzymes, and those of L curvatus and L mesenteroides subsp. mesenteroides were also sensitive to lipase and $\alpha$-amylase as well as to proteolytic enzymes. The bacteriocins from the strains of Lactobacillus sp. and a strain of L. brevis were resistant to autoclaving.