• Korean Journal of Food Science and Technology
• /
• v.24 no.6
• /
• pp.528-534
• /
• 1992

Growth stimulatory material for lactic acid bacteria was extracted from radish and radish green juice and its growth stimulatory effect was tested. Dried methanol-precipitated growth stimulatory material was lightly grayish white powder, Its ash content is 44% and approximately 50% of the ash is sulfur. It has reddish brown color upon solubilization in water. The material had unchanged stimulatory effect when it was treated with proteinase or pectinase, or ashed. The growth stimulatory activity was dialyzable. The material was able to counteract the growth inhibitory effect of EDTA. When selected lactic acid bacteria were grown at $30^{\circ}C$ for 24 hours in peptone(0.5%)-yeast extract(0.5%)-glucose(2%) broth with and without 0.5% growth stimulatory material, the material stimulated the growth of Lactobacillus plantarum, L. fermentum, L. leichmanii, L. sake, L. brevis, L. acidophilus, L. casei, Pediococcus pentosaceus, Leuconostoc mesenteroides, Streptococcus faecalis, S. lactis, S. cremoris and S. thermophilus by 19, 1833, 133, 444, 840, 32, 14, 18, 6, 17, 4, 5 and 4 times, respectively.

• Korean Journal of Food Science and Technology
• /
• v.43 no.2
• /
• pp.169-175
• /
• 2011

The ${\beta}$-xylosidase (EC 3.2.1.37) production capabilities of lactic acid bacteria in the genus Leuconostoc, isolated from a variety of kimchi (fermented vegetables), were examined. The intracellular levels of ${\beta}$-xylosidase were similar to the extracellular levels, when most Leuconostoc lactic acid bacteria were grown in a medium containing xylose as the carbon source. Intracellular ${\beta}$-xylosidase with a maximum activity of $1.2{\pm}0.1units/mL$ (mean${\pm}$standard error) was obtained from Leuconostoc lactis KCTC 13344, which was isolated from fermented Chinese cabbage. The optimum reaction conditions for Leu. lactis KCTC 13344 ${\beta}$-xylosidase activity were pH 6.0 and $30^{\circ}C$, and the addition of most divalent cations, except zinc, to the reaction mixture resulted in a slight increase in enzyme activity. Compared with a media containing other carbon sources, the ${\beta}$-xylosidase activity was 5 times higher when Leu. lactis KCTC 13344 was grown in a medium containing xylose as carbon source. Zymographic analysis indicated that the synthesis of Leu. lactis KCTC 13344 ${\beta}$-xylosidase (approximate size, 64 kDa) is induced by xylose. A maximum intracellular ${\beta}$-xylosidase activity of $7.1{\pm}0.3units/mL$ was obtained in a batch cultivation in an MRS medium containing 30 g/L xylose.

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.6
• /
• pp.758-767
• /
• 2014

In this study, we selected an Escherichia coli strain (E. coli MG 1655) metabolizing arabinose derived from acid hydrolyzed black liquor as a carbon source and investigated effect of organic acids (acetic acid, formic acid, and lactic acid) presented in black liquor on growth of the E. coli MG 1655. We measured growth of E. coli MG 1655 under various concentration of each and combined three kinds of organic acids. The E. coli MG 1655 shows tolerance to acetic acid, lactic acid and formic acid at these concentrations ($1.0g/{\ell}$ acetic acid, $1.2g/{\ell}$ lactic acid and $0.8g/{\ell}$ formic acid, respectively), but displays some growth retardation over $1.5g/{\ell}$ acetic acid, lactic acid $2.0g/{\ell}$, and formic acid $1.2g/{\ell}$, respectively. In addition, formic acid was shown to be a critical factor affecting growth of the E. coli MG 1655 in the presence of three kinds of organic acids. These results indicate that the inhibitors should be removed at least $1.0g/{\ell}$ of acetic acid, $1.2g/{\ell}$ of lactic acid, $0.8g/{\ell}$ of formic acid for normal cell growth required for high yield fermentation. In addition, there is a need to construct recombinant strains that may be resistant to the same or higher organic acids concentration (> $1.2g/{\ell}$) in the growth.

• Food Science and Preservation
• /
• v.24 no.2
• /
• pp.237-245
• /
• 2017

Lactic acid fermentation of Flammulina velutipes (FV) powder was optimized to produce higher content of ${\gamma}-aminobutyric$ acid (GABA). FV powder (10%) was fermented with 0.5% yeast extract, 1% glucose, 5% mono sodium-L-glutamate (MSG) by Lactobacillus plantarum EJ2014 for 5 days at $30^{\circ}C$. The pH decreased from 6.1 to 4.4 for first 2 days after then increased to 6.2 for following 5 days. While the acidity increased from 0.5% to 1.3% for 2 days, after then decreased to 0.4% for 5 days. Viable cell count showed higher value of $2.2{\times}10^9CFU/mL$ after fermentation for 5 days. In particular, 3.54% MSG as a substrate was completely utilized during lactic acid fermentation, indicating higher 2.31% GABA content. The fermented FV powder showed higher antioxidant properties than that of un-fermented FV power. $IC_{50}$ values of DPPH radical scavenging and ABTS radical scavenging activities were 1.11 mg/mL and 2.58 mg/mL, respectively. Conclusively, natural fermented seasoning from the lactic acid fermentation of 30g of FV powder and 1 g of roasted wheat bran could provide the functional ingredients with 17% GABA, probiotics and dietary fiber, which is used for health food and functional seasoning.

• Research in Plant Disease
• /
• v.20 no.3
• /
• pp.227-233
• /
• 2014

The mixture (MX) of acetic acid (AA) and lactic acid (LA) was examined for its effectiveness in the control of the pine wood nematode Bursaphelenchus xylophilus contaminated in cymbidium culture medium. Nematode mortality in vitro was nearly 100% in AA and MX at the concentrations of 5.0-1.0% (pH 2.6 - 4.2) and in LA only at 5.0% (pH 3.5), but lowered at concentrations of 0.5-0.1% (pH 5.1-6.9) more significantly in LA than AA and MX. MX of most concentrations caused higher nematode mortality than the average response to AA and LA. All treatments of MX (0.5% and 0.25%), fosthiazate (standard and double concentrations) and culture dilution of Paenibacillus polymyxa GBR-1 ($10^7$colony-forming units/ml) reduced significantly the nematode populations in the cymbidium culture medium, compared to non-treatment control, with no significant difference among the treatments. No phytotoxicity occurred in all treatments. pH of the medium with the time after treatment and growths of 2-year-old cymbidium were not significantly different among treatments. Considering the safety and price of the organic acids, use of MX in the processes for culturing cymbidium may be a practically reliable and eco-friendly way in the control of the quarantine nematode in cymbidium.

• Journal of Life Science
• /
• v.25 no.7
• /
• pp.819-825
• /
• 2015

The use of fructose-containing sports beverage drinks has increased in recent years, especially at sport events, because of their reported ergogenic effects. However, the ingestion of low to moderate doses of caffeinated energy drinks has been associated with adverse side effects such as insomnia or increased nervousness. The purpose of this study was to investigate the effects of fructose beverage supplementation on cardiopulmonary function, blood lactate levels, and inflammatory reactions. We recruited 8 young adult subjects from D university and measured their cardiopulmonary functions before and after supplementation with sports beverage drinks. We also measured blood lactate and inflammatory reactions after a 20 min recovery period. Exercise time, maximal oxygen uptake (V0₂max), and AT HRmax were significantly increased (p<0.05) in the period of before and after sports beverage supplementation. However, no significant differences were observed in RPE, AT RER, V0₂max RER, AT V0₂max, and maximum heart rate (HRmax). Lactate levels also significantly decreased after 20 min recovery with sports beverage supplementation. Sports beverage supplementation therefore may enhance maximal V0₂max and increase the exercise duration time. These drinks may also be helpful in promoting rapid recovery of fatigue variables and increasing exercise performance time.

• Food Engineering Progress
• /
• v.14 no.4
• /
• pp.292-298
• /
• 2010

Wheat germ contains the glycosylated forms of 2-methoxy-p-benzoquinone (2-MBQ) and 2,6-dimethoxy-p-benzoquinone (2,6-DMBQ), both of which have antimicrobial and immunostimulatory effects. Conversion of glycosylated 2-MBQ and 2,6-DMBQ to their more functional unglycosylated forms requires enzymatic action of $\beta$-glucosidase. We investigated the applications of lactic acid bacteria and yeast that produce $\beta$-glucosidase as starters for production of unglycosylated 2-MBQ and 2,6-DMBQ from wheat germ. Lactobacillus zeae and Pichia pijperi were selected through $\beta$-glucosidase enzyme assays for 37 yeast strains and five strains of lactic acid bacteria. Lb. zeae was more efficient than P. pijperi at producing 2-MBQ and 2,6-DMBQ from wheat germ. After 48 hr of fermentation with a mixed culture of Lb. zeae and P. pijperi, the concentration of 2-MBQ was 0.46${\pm}$0.07 mg/g, indicating an approximately 1.6-fold higher concentration than that obtained by pure culture of Lb. zeae. However, the concentration of 2,6-DMBQ was not significantly enhanced by fermentation with a mixed culture of Lb. zeae and P. pijperi.

• Korean Security Journal
• /
• no.17
• /
• pp.131-141
• /
• 2008

The porpuse of present study was to examine the effects of working time on fatigue and fatigue induced factor in private guard and security. The munber of private guard on which this study has been conducted in 200, who work at large conmpanies, medium or small companies and the like as located in Seoul and kyonggi. In this study blood lactate, phosphorus and ammonia were measred to see the level of fatigue. There was significant difference in blood lactate, phosphorus ammonia and fatigue between working hours(P<0.05). in view of the results of this study, it can be thought that fatigue is more affected by working hours In summary, these results are interpreted to mean that 1) fatigue levels and blood fatigue induced factor (lactate, phosphorus, ammonia) increase due to a rise in working hours.

• Microbiology and Biotechnology Letters
• /
• v.26 no.5
• /
• pp.373-378
• /
• 1998

This study was performed to investigate antimicrobial effects and their actions of the ethanol extracts of 12 spices against Lactobacillus plantarum and Leuconostoc mesenteroides, which are related to Kimchi fermentation. The cardamon, thyme, and cumin ethanol extracts among 12 spices showed antimicrobial activities against Lac. plantarum, not against Leu. mesenteroides through paper disc method. The growth of Lac. plantarum was inhibited in MRS broth containing each extracts of cardamon (>4%), thyme (>4%) and cumin (>1%). SDS-PAGE and transmission electron micrographs showed that the cell walls and membranes were disrupted and the cytoplasmic components were leaked in strains treated with ethanol extracts.

• Membrane Journal
• /
• v.5 no.1
• /
• pp.44-57
• /
• 1995

A mathematical model was proposed to describe the behavior of the liquid emulsion membrane(LEM) conraining sodium carbonate as internal stripping reagent. Experimental results of the batch extraction of lactic acid were compared with computed results by using the model. it was found that the model computations could predict fairly well the effects of parameter variations such as the carrier concentration, the stripping reagent concentration, the stirrer speed and the treatment ratio. An attempt has been made to reduce emulsion swelling which is one of the main problem of LEM. As the additives for swelling control, liquid paraffin, n-decanol, cyclohexanone and Span 85 were used. All the additives that were investigated tend to reduce the quantity of swelling to some extent. Cyclohexanone was found not only to reduce the swelling but also to increase largely the acid transport rate.