• Journal of Microbiology and Biotechnology
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• v.22 no.9
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• pp.1224-1229
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• 2012

Puerarin (P), an isoflavone derived from kudzu roots, has strong biological activities, but its bioavailability is often limited by its low water solubility. To increase its solubility, P was glucosylated by three dextransucrases from Leuconostoc or Streptococcus species. Leuconostoc lactis EG001 dextransucrase exhibited the highest productivity of puerarin glucosides (P-Gs) among the three tested enzymes, and it primarily produced two P-Gs with a 53% yield. Their structures were identified as ${\alpha}$-$_D$-glucosyl-($1{\rightarrow}6$)-P (P-G) by using LC-MS or $^1H$- or $^{13}C$-NMR spectroscopies and ${\alpha}$-$_D$-isomaltosyl-($1{\rightarrow}6$)-P (P-IG2) by using specific enzymatic hydrolysis, and their solubilities were 15- and 202-fold higher than that of P, respectively. P-G and P-IG2 are easily applicable in the food and pharmaceutical industries as alternative functional materials.

• Korean Journal of Food Science and Technology
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• v.19 no.2
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• pp.151-156
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• 1987

Four types of soy milk prepared from soybean, defatted soybean, soy protein concentrate (SPC) or soy protein isolate (SPI) were fermented with Lactobacillus acidophilus, L. bulgaricus, L. casei, Leuconostoc mesenteroides or Streptocroccus lactis. Growth and acid production by each organism in soy milks were investigated. Acid production by L. acidophilus was miximum in soy milk while acid production by other organisms was maximum in defatted soy milk. All the organisms produced least amount of acid in SPI-milk. Addition of yeast extract (0.5) to four types of soy milks stimulated acid production by lactic acid bacteria, particularly in case of L. acidophilus. Higher concentration of total solids in soy milks resulted in better growth and more acid production by L. acidophilus and L. bulgaricus.

• Korean Journal of Food Science and Technology
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• v.16 no.3
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• pp.285-290
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• 1984

Growth characteristics of six lactic acid bacteria in whey-soy milk mixtures were investigated to obtain basic informations for processing cheese-like product by coprecipitation of whey and soy proteins. Streptococcus cremoris and Lactobacillus acidophilus produced more aicd than other lactic acid bacteria both in whey-soy milk mixture and in soy milk. Lactic acid fermentation was accelerated in whey-soy milk mixture than in soy milk with all the lactic aicd bacteria, and specially with S. lactis and S. cremoris in great extent. The number of viable cell of 1:1 mixed culture of S. lactis and S. cremoris in whey soy milk mixture was about 10 times than in soymilk. It was mainly the effect of lactose in the whey that increased the acid production by lactic aicd bacteria in whey-soy milk mixture although the degree of acceleration depended on the ability of microorganism to use carbohydrates. The optimum amount of lactose added to soy milk to accelerate the acid production was 0.8g/100ml soy milk.

• Korean Journal of Agricultural Science
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• v.48 no.3
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• pp.575-587
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• 2021

This study was carried out to investigate the effects of supplementation with a Bifidobacteria enhanced yogurt (BE0623 yogurt), which includes Bifidobacterium lactis BB12, Lactobacillus acidophilus, Streptococcus thermophilus, and Bifidobacterium lactis, in the management of irritable bowel syndrome (IBS) using animal models and clinical trials. In a rat study, a loperamide-treated group (LOP) showed reduced water content in fecal pellets but showed an increased number of fecal pellets in the distal colon. In addition, the BE0623 yogurt (L-BE0623Y) group had the fewest fecal pellets in the distal colon. Regarding the serum lipid parameters, the LOP group had a high-density lipoprotein (HDL)/total cholesterol ratio that was 43% lower than that of a normal water group (NOR), but the outcome for the L-BE0623Y group was 27% lower than the NOR group. In a human study, 116 adults with IBS were sampled as subjects and fed 300 mL of yogurt per day for an eight week period. There was an IBS improvement in the L-BE0623Y and commercial yogurt (L-CY) groups, though flatulence, stool consistency and frequency of defecation outcomes were also noted. Specifically, the L-BE0623Y treatment group showed significant effects with regard to defecation duration and urgency after the consumption of the yogurt used in this study. These results suggest that the Bifidobacteria-enhanced yogurt has superior effects with regard to relieving loperamide-induced constipation in rats and that regular consumption of L-BE0623Y is effective to improve IBS in humans.

• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.209-218
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• 2021

This study was carried out to investigate the effects of Bifidobacteria growth promoter BE0623 and a dietary fiber supplement, which included Bifidobacterium lactis BB12, Lactobacillus acidophilus, Streptococcus thermophilus, and Bifidobacterium lactis. In fermented milk containing BE0623, the viable cell count of Bifidobacteria significantly increased by about 45 to 75 times compared to the control, and the titratable acidity increased, whereas the pH decreased. All fractions obtained by isolating BE0623 had Bifidobacteria growth effect. Acacia dietary fiber is a pale yellow powder. It has a viscosity of 60 to 100 cPs and a pH between 4.1 and 5.0. Its general components are less than 10% moisture, more than 90% dietary fiber, and less than 4% ash. The optimal addition ratio of Bifidobacteria growth promoting material was determined to be 0.05%. The general components of the manufactured fermented milk were carbohydrate 17.85%, protein 3.63%, fat 3.00%, and dietary fiber 2.95%. During storage of the fermented milk for 24 days, its titratable acidity, viscosity, and sugar content all met the criteria. In addition, the viable cell counts of Bifidobacteria and lactic acid bacteria in the fermented milk were 1.7 × 10⁸ CFU·mL^-1 and 1.5 × 10⁷ CFU·mL^-1, respectively, and Escherichia coli was negative. There was no significant difference between the control group and the treatment group in the sensory evaluation of sweet, sour, weight, and flavor, and the preference for the treatment group was excellent. The acceptability of the fermented milk of the treated group according to the storage period was excellent in terms of color, flavor, and appearance.

• Korean Journal of Food Science and Technology
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• v.10 no.2
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• pp.231-236
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• 1978

It has been investigated that preparation of cheese-like product from defatted soybean milk and changes during 6 weeks' ripening. Obtained results were as follows: 1. Defatted soybean milk was fermented at $37^{\circ}C$ for 4 hours with Streptococcus lactis YUFE L-4 without addition of any other carbon sources. 2. Optimum concentration of coagulant such as $MgCl_2{\cdot}6H_2O$ and $CaCl_2$ were 0.0125M and 0.0375M, respectively. 3. Coagulating time for 30 minutes was sufficient to make curd. 4. Optimal reaction temperature for coagulating were $50^{\circ}C$. 5. After 6 weeks' ripening, moisture content was approximately $62{\sim}63%$. Water and 10%-TCA soluble nitrogen contents of soybean cheese with Asp. saitoi protease were higher than those of Mucor rennet. Water soluble nitrogen content of Asp. saitoi protease cheese was 50.5% and 10%-TCA soluble nitrogen was 27.5%.

• Korean Journal of Food Science and Technology
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• v.24 no.6
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• pp.528-534
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• 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 Microbiology
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• v.50 no.3
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• pp.216-222
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• 2014

their survival rates could be affected by various factors such as diet, stress, senescence, and antibiotics. This study was performed to evaluate the influence of various spices (garlic, ginger, scallion, onion, Chungyang red pepper, and red pepper) which have antimicrobial properties and used frequently in Korean diet, and propolis on probiotics isolated from Koreans. As a result, most Korean probiotic strains were resistant to all spices tested and propolis, and the growth rates of some Korean probiotic strains (Bifidobacterium lactis, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus rhamnosus, Streptococcus thermophiles) were even increased by specific spices or propolis. But on the other hand, the growth rates of most of european probiotic strains were reduced by various spices or propolis, and the growth rates of a few european probiotic strains (L. helveticus, S. thermophiles) were greatly decreased in the presence of specific spices. Likewise, all commercial probiotic products including Korean probiotic strains were rarely affected by spices tested. However, european probiotic product tended to be greatly reduced by garlic, onion, scallion, and propolis. Therefore, these results indicate that probiotic strains isolated from Korean have the strong viability and resistance to various spices with antimicrobial properties, so that they might be appropriate for Korean intestine.

• Journal of Microbiology
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• v.43 no.4
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• pp.345-353
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• 2005

The complex ecosystem of intestinal micro flora is estimated to harbor approximately 400 different microbial species, mostly bacteria. However, studies on bacterial colonization have mostly been based on culturing methods, which only detect a small fraction of the whole microbiotic ecosystem of the gut. To clarify the initial acquisition and subsequent colonization of bacteria in an infant within the few days after birth, phylogenetic analysis was performed using 16S rDNA sequences from the DNA iso-lated from feces on the 1st, 3rd, and 6th day. 16S rDNA libraries were constructed with the amplicons of PCR conditions at 30 cycles and $50^{\circ}C$ annealing temperature. Nine independent libraries were produced by the application of three sets of primers (set A, set B, and set C) combined with three fecal samples for day 1, day 3, and day 6 of life. Approximately 220 clones ($76.7\%$) of all 325 isolated clones were characterized as known species, while other 105 clones ($32.3\%$) were characterized as unknown species. The library clone with set A universal primers amplifying 350 bp displayed increased diversity by days. Thus, set A primers were better suited for this type of molecular ecological analysis. On the first day of the life of the infant, Enterobacter, Lactococcus lactis, Leuconostoc citreum, and Streptococcus mitis were present. The largest taxonomic group was L. lactis. On the third day of the life of the infant, Enterobacter, Enterococcus faecalis, Escherichia coli, S. mitis, and Streptococcus salivarius were present. On the sixth day of the life of the infant, Citrobacter, Clostridium difficile, Enterobacter sp., Enterobacter cloacae, and E. coli were present. The largest taxonomic group was E. coli. These results showed that microbiotic diversity changes very rapidly in the few days after birth, and the acquisition of unculturable bacteria expanded rapidly after the third day.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1358-1364
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• 2000

A mixed culture of bacteriocin-producing lactic acid bacteria and yeast was used to prepare unique fermented fruit and vegetable beverage which contains bacteriocin. Fruit and vegetable broth fermented by Lactococcus lactis 11454 showed inhibitory activity against foodborne pathogens such as Listeria monocytogens and Staphylococcus aureus, and Streptococcus mutans which is a major causative agent for dental caries. Bacteriocin was detected at the end of fermentation of fruit and vegetables and its antimicrobial activity was stable for 5 weeks during storage at $4^{\circ}C$. These results suggest that the presence of bacteriocin in beverages during fermentation and storage will provide a safeguard against foodborne pathogens and spoilage bacteria. To improve flavor of the fermented broth, post-fermentation of the fermented broth was carried out at $4^{\circ}C$ by using yeast isolated from raw material mixture. Total acidity of the post-fermented broth was slightly decreased, but significant increase in the concentration of succinic acid was observed in the post-fermented broth. It was also observed that bitter and disagreeable taste compounds such as phthalates were decreased, and mild acidic and fruity flavor esters and alcohols were increased by the post-fermentation of the fermented broth with yeast.