• The Journal of the Korean Society for Microbiology
• /
• v.15 no.1
• /
• pp.55-62
• /
• 1980

Eleven strains of lactobacilli were isolated from fermented milk of 9 companies. They were classified 3 strains as L. bulgaricus, 2 strains as L. plantarum, 2 strains as L. cellobiosus, 1 strain as L. lactis, 1 strain as L. acidophilus, 1 strain as L. casei subsp. casei and 1 strain as L. casei subsp. tolerans. And these strains were examined for drug resistance, transferability and transfer frequency of R plasmid. Most of isolates were sensitive to tetracycline(TC), penicillin(PC), and erythromycin(EM), but some strains were resistant to streptomycin(SM), chloramphenicol(CP), ampicillin(AP), kanamycin(KM), and nalidixic acid(NA). All of isolates were resistant to two or more drugs and 6 different drug resistant patterns were found. The most frequently encountered patterns were NA AP CP SM KM(5 strains) followed by NA AP CP KM(2 strains), NA AP CP SM(1 strain), NA AP CP(1 strain), NA CP(1 strain) and NA AP(1 strain). Tranfer experiment of drug resistance showed that of all 11 resistant strains, 9 strains transferred R plasmid determining AP(6 strains) or AP SM(3 strains) to a recipient, E. coli ML 1410 strain with $2.8{\times}10^{-5}-1.5{\times}10^{-1}%$ of transfer frequency. These results indicate that lactobacilli conjugally transfer their resistance to E. coli.

• The Korean Journal of Food And Nutrition
• /
• v.26 no.3
• /
• pp.398-403
• /
• 2013

To manufacture the fermented tea with hygienic quality, green tea was fermented using Bacillus subtilis, Saccharomyces cerevisiae and Lactobacillus bulgaricus and mineral composition, total amino acid content and antioxidative activity changes were evaluated during the fermentation period. Minerals detected in the fermented tea, the Ca, Fe, Zn, Mg and Mn minerals were detected. Ca and Mg are relatively large compared to other mineral content. Total amino acid content of the control was 3.57%, but total amino acid of fermented teas were higher (3.68~3.85%) during fermentation 20 days. Metal chelating activity of control was 55.11%, Metal chelating activity of the fermented tea using B. subtilis was the highest. In reducing power, O.D. value of the control was 2.27, three kinds of fermented tea were lower than that of control. The fermented teas increased lipid peroxidation inhibition compared to the blank test.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.2
• /
• pp.254-260
• /
• 1995

Yogurt base were prepared from milk added with skim milk powder or Aloe vera powder and femented with lactic acid bacteria(the single or mixed strain of Lactobacillus bulgaricus and Streptococcus thermophilus). The yogurt product were evaluated for acid production(pH, titratable acidity), number of viable cell, viscosity, sensory property and quality-keeping property. The composition of organic acid were also analyzed by HPLC. Addition of Aloe vera remarkably accelerated acid production, and titratable acidity of Aloe vera yogurts(1.293∼1.407%) after 24 hours incubation was higher than that of yogurts added with only skim milk powder(9.98∼1.110%). Yogurt fermented with the mixed strain of L. bulgaricus and Sc. thermophilus was more acidic than that of single strains. The propagation of lactic acid bacteria was stimulated by Aloe vera and the number of viable cell after 24 hours incubation were above 9.87log CFU/ml. Viscosity of Aloe vera yogurt(3,860∼4,300CPS) was higher than that of yogurt with only skim milk powder(2,402∼2,604CPS). The overall sensory score of Aloe vera yogurt femented by mixed strain was the best of tested yogurt. When yogurt with Aloe vera was kept at 5℃ for 15 day, it's quality-keeping property was relatively good. The major organic acid of Aloe vera yogurt was lactic acid and lactic acid content of yogurt increased by addition of Aloe vera powder. The citric acid content decreased wtih fermentation and malonic acid, pyroglutaric acid and α-ketoglutaric acid were analyzed out a little.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.30 no.1
• /
• pp.1-7
• /
• 1997

In order to utilize fish by-products from the skipjack tuna (Katsuwonus pelamis) canning manufactures Lactobacillus buigaricus KCTC 3188 and L. piantarum KCTC 1048 were used as a starter culture for the preparation of fermented fish silage with skipjark tuna viscera. The optimum temperature and pH on barterial growth and lactic acid production of L. bulgaricus and L. plantarum in MRS broth were $35^{\circ}C$ and around pH 6.0, respectively. And the optimum concentrations of the carbohydrate sources added to the broths were $7\%$ for dextrose and $10\%$ for molasses on the basis of total weights of skipjack tuna viscera. The pH of acid treated skipjack tuna viscera silage (ASS) slightly increased from 4.0 to 4.5, while that of fermented skipjack tuna viscera silages by the use of lactic acid bacterias (FSS) was significantly declined from 5.9 to about 40 after 42 days of storage at $35^{\circ}C$. Though the content of volatile basie nitrogen (VBN) in ASS was lower than those of FSS after 42 days of storage at $35^{\circ}C$, VBN content in silages slightly increased from an initial value of $62\~65{\cdot}mg/100g$ to final value of $113\~155\;mg/100g$ over 42 days. The fermented silage by L. piantarum reached a maximum concentration of amino nitrogen and showed $81\%$ of hydrolysis degree after 4 days of storage at $35^{\circ}C$.

• Korean Journal of Food Science and Technology
• /
• v.23 no.5
• /
• pp.587-592
• /
• 1991

The curd yogurt was prepared from milk or milk added with skim milk powder or four types of rice powder. Acid production by lactic acid bacteria in milk containing additive of 2% (w/v) was investigated and quality of curd yogurt (sensory property and keeping quality) was examined. Some organic acids in curd yogurt were analyzed by HPLC. Four types of rice powder, particularly brown rice, stimulated acid production by lactic acid bacteria more than control (milk yogurt). Among four organisms tested, Leuconostoc mesenteroides and Lactobacillus bulgaricus produced more acid than L. casei and L. delbrueckii. HPLC analysis of organic acids in curd yogurt showed that the amount of lactic acid markedly increased during the fermentation by L. bulgaricus for 24 hours while the amount of citric acid markedly decreased. Addition of rice powders to milk slightly reduced sensory property of curd yogurt. Among four types of rice powder tested, tongil rice added sample showed better sensory acceptability than other samples. When curd yogurt was kept at $5^{\circ}C$ for two weeks, acidity and number of viable cells of curd yogurt were not changed.

• Journal of Food Hygiene and Safety
• /
• v.13 no.2
• /
• pp.99-105
• /
• 1998

Pectin hydrolysate prepared from citrus pectin by enzymatic hydrolysis has antimicrobial activity. The antimicrobial activity was increased by its hydrolyzing rate and it was rapidly increased after 70% hydrolysis of the pectin. The antibacterial activity of pectin hydrolysate against Escherichia coli ATCC 11229 was the strongest at pH 4.9~5.5, but it diminished slightly at neutral pH values. The antibacterial activity of pectin hydrolysate was stronger than those of against molds and yeasts. The growth of bacteria submitted to this test except lactics was completely inhibited for 48 hrs at $35^{\circ}C$ by adding 2.0~3.0% pectin hydrolysate. While the growth of Lactococcus lactis ATCC 19435 and Lactobacillus bulgaricus and Penicillium funiculosum ATCC 11797 were reached about 60~70% compared with those of the controls in the same condition. But there was no significant effect on the growth of the yeasts. The antibacterial effect of pectin hydrolysate was significantly stimulated by addition of glycine, ethanol, sodium ascorbate, sodium chloride and sodium acetate. The shelf life of Kimchi containing 1.0% pectin hydrolysate was prolonged above 15 days at $4^{\circ}C$ than that of its control. In case of whitish bean jam viable cell counts were inhibited about 2 log cycles by 10 days at $25^{\circ}C$. According to these results, author can sincerely suggest that pectin hydrolysate will be used as a natural food preservative for inhibition of common bacterial growth without inhibition of lactics and yeasts.

• The Korean Journal of Food And Nutrition
• /
• v.25 no.2
• /
• pp.291-298
• /
• 2012

One of the main microorganisms causing diarrheal diseases is Campylobacter jejuni. Purslane or Portulaca oleracea is an edible plant containing polyphenols that has been widely used as a folk remedy for treatment of diarrhea for a long time. This study was performed to investigate the antimicrobial activity of fermented P. oleracea extracts made with probiotics and plant-origin lactic acid bacteria(PLAB) isolated from P. oleracea against C. jejuni. Lactobacillus rhamnosus, L. acidophilus, L. bulgaricus, L. delbrueckii, L. plantarum, Leuconostoc mesenteroides and Bifidobacterium longum were applied to P. oleracea to make a fermentation broth of purslane. Leuconostoc mesenteroides and the lactic acid bacteria isolated from P. oleracea grew best in the fermentation broth of P. oleracea extracts when the broth was combined with 2% yeast extract, 1% peptone, and 0.05 to 1% potassium phosphate. The number of viable cells in the fermentation broth containing purslane extracts after 48 hours increased to $1{\times}10^{12}\;CFU/m{\ell}$ and remained at $1.3{\times}10^{10}\;CFU/m{\ell}$ after refrigeration for 2 weeks. The pH and acidity of purslane-fermented broth after 48 hours of fermentation was 3.7 and 3.14, respectively, which show that the fermentation broth was within the range of the general standards of fermented dairy products. The antimicrobial activity of the fermented P. oleracea extracts was determined using the liquid culture method. The 10 $mg/m{\ell}$ concentration of the fermented P. oleracea extract made with Leuconostoc mesenteroides and the lactic acid bacteria isolated from purslane showed the strongest antimicrobial activity against C. jejuni. The fermentation broth of purslane with the probiotics retarded the growth of C. jejuni for 48 hours at $42^{\circ}C$.

• Korean Journal of Food Science and Technology
• /
• v.22 no.6
• /
• pp.700-706
• /
• 1990

The curd yogurt was prepared from milk or milk added with skim milk powder or soy proteins. Acid production by lactic acid bacteria in milk containing additive of 2% was investigated and quality of curd yogurt(sensory property and keeping quality) was examined. Some organic acids in curd yogurt were analyzed by HPLC. The soy proteins, particularly defatted soy flour or soy flour, stimulated acid production by lactic acid bacteria more than skim milk powder. Among the four organisms tested, Leuconostoc mesenteroides and Lactobacillus bulgaricus produced more acid than L. casei and L. delbrueckii. HPLC analysis of organic acids in curd yogurt showed that the amount of lactic acid and acetic acid markedly increased during the fermentation by L. bulgaricus for 24 hours while the amount of citric acid markedly decreased. The major organic acid produced during the fermentation was lactic acid. Addition of soy proteins to milk reduced sensory property of curd yogurt. Among the soy proteins tested, soy protein concentrate or soy protein isolate added sample showed better sensory acceptability than other samples. When curd yogurt was kept at $5^{\circ}C$ for two weeks, titratable acidity, pH and number of viable cells of curd yogurt were not changed.

• Korean Journal of Food Science and Technology
• /
• v.29 no.3
• /
• pp.533-538
• /
• 1997

Lactobacillus bulgaricus and Kluyveromyces lactic were inoculated to Jangyeob and Jinpum soymilks single or together after the addition of different amounts of lactose to increase the formation of lactic acid and sensory evaluation. The decrease of pH and the increase of acid production during the fermentation of soy yogurts were more effective when lactose was added. And the single culture method was more effective in decreasing pH and in increasing acid production than the mixed culture method. Without lactose, the growth of lactic acid bacteria in samples increased by mixed culture method than by single culture method. However, the growth of lactic acid bacteria increased more in the by single cultured samples than in the mixed cultured samples by the addition of lactose. Beany flavor decreased more in soy yogurts compared with Jangyeob and Jinpum soy milks, and Jinpum soy yogurts had less beany flavor than Jangyeob soy yogurts. In sour taste, Jangyeob soy yogurt prepared by mixed culture for 36 hr incubation with 4% lactose showed the poorest score, while soy yogurts containing 2% lactose showed significantly better scores and no significant difference compared with milk yogurt. Soy yogurts containing 2% lactose showed no significant difference in overall acceptability compared with milk yogurt.

• Journal of Mushroom
• /
• v.13 no.1
• /
• pp.50-55
• /
• 2015

Glucan has been shown to have a significant role in the activation of the immune system, including increased activity of macrophages and so on. Sparassis latifolia (formerly S. crispa) is an edible mushroom abundant in dietary fiber and widely known to contain high levels of ${\beta}$-glucan. In the present study, fermentation broths containing soluble ${\beta}$-glucan were prepared by fermentation with mushrooms with four Lactobacillus species (L. plantarum subsp. Plantarum, L. acidophilus, L. helveticus, and L. delbrueckii subsp. Bulgaricus). After culturing four Lactobacillus spp. in MRS broth, each Lactobacillus was inoculated into MRS broth containing S. latifolia powder 5% (w/v) at $37^{\circ}C$ in an anaerobic incubator for five days. It showed that the ${\beta}$-glucan contents were different in each fermentation sample. The suitable conditions for the preparation of mushroom fermentation broths were investigated and discussed.