• Journal of Dairy Science and Biotechnology
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• v.30 no.1
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• pp.45-53
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• 2012

Lactobacillus acidophilus isolated from the feces of a 7-day-old breast-fed infant was characterized to examine the scope of its commercial use. Forty-three Lactobacillus strains, which could grow at pH 5.5, were isolated. From these Lactobacillus isolates, 14 Lactobacillus strains were selected, which demonstrated more than 80% viability and homofermentative lactic fermentation. Finally, 9 L. acidophilus strains (NB 201~NB 209) were identified as candidate strains based upon biochemical properties, carbohydrate utilization, and cellular fatty acid composition. L. acidophilus isolates demonstrated a survival rate of more than 80% when exposed to pH 2.5 for 2 h. In particular, L. acidophilus NB 204 showed a strong acid tolerance, with a 71% survival rate even at pH 2.0. L. acidophilus isolates also manifested high bile acid tolerance; more than 87% of the cells survived on agar containing 1% bile extract, except for L. acidophilus NB 206, which showed a 73% survival rate. All L. acidophilus isolates were confirmed to have proteolytic activity; L. acidophilus NB 204 and NB 209 yielded higher levels of TCA-soluble peptides and free amino acids. The ${\beta}$-galactosidase activity of the L. acidophilus isolates was in the range of 1.97~2.45 units/mL.

• Journal of Animal Science and Technology
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• v.50 no.4
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• pp.509-518
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• 2008

This experiment was conducted to investigate enzyme activity, antimicrobial activity, and antibiotics susceptibility of Lactobacilli strain(Lactobacillus reuteri BLA5, Lactobacillus crispatus BLA7, Lactobacillus reuteri BLA9, Lactobacillus amylovorus LLA7, Lactobacillus crispatus LLA9, Lactobacillus vaginalis LLA11) isolated from chicken ceca and were selected by organic acid synthesis, acid tolerance, bile salt tolerance. The enzymes activities were different among strains of Lactobacilli. The amylase activity and lipase activity of Lactobacillus were high but cellulase activity and protease activity of that were low. Lactobacillus culture showed high antimicrobial activity against E. coli but low antimicrobial activity against Salmonella. The inhibitory factor of Lactobacilli isolated from chickens’ cecum on E. coli was low pH by organic acid. All of Lactobacillus isolated from chicken’s cecum were susceptible to ampicillin and amoxicillin but weren’t susceptible at the optimum level of feed additive antibiotics(virginiamycin and salinomycin).

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.438-445
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• 2015

The production of GABA was optimized by co-cultivation of immobilized Lactobacillus plantarum K154 (ILK) with Ceriporia lacerata cultures. The mycelial culture of C. lacerata was performed in a defined medium containing 3% glucose, 3% soybean flour, and 0.15% $MgSO_4$ in a submerged condition for 7 days at $25^{\circ}C$, resulting in the production of 29.7 g/L mycelia, 3.1 g/L exopolysaccharides, 2% (w/w) ${\beta}$-glucan, 68.96 unit/mL protease, and 10.37 unit/mL ${\alpha}$-amylase. ILK in C. lacerata culture showed viable cell counts of $3.13{\time}10^9CFU/mL$ for immobilized cells and $1.48{\time}10^8CFU/mL$ for free cells after 1 day. GABA production in the free and immobilized cells was 9.96 mg/mL and 6.30 mg/mL, respectively, after 7 days. A recycling test of ILK in the co-fermentation was consequently performed five times at $30^{\circ}C$ for 15 days, resulting in the highest production of GABA. GABA could also be efficiently overproduced by co-cultivation with the produced polysaccharides, ${\beta}$-glucan, peptides, and probiotics.

• The Korean Journal of Food And Nutrition
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• v.28 no.6
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• pp.956-964
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• 2015

Probiotics is known improve the microenvironment of colon; however, the metagenomic DNA study of its lactic acid bacteria in constipation induced by loperamide is not clearly understood. In the present study, we investigated the reduction of the lactic acid bacteria in case of constipation, in normal and loperamide-induced rat. Lactic acid powder (lactic acid bacteria 19) was prepared from Chong Kun Dang Pharmaceutical Corporation. After 2 weeks of oral administration, the group treated with the higher concentration of lactic acid bacteria ($10^9CFU/mL$ per kg of body weight) following loperamide treatment was the most effective in increasing number, weight, and water content of feces. A similar but significant increase was found in the group treated with lower concentration of lactic acid bacteria ($10^7CFU/mL$ per kg of body weight) after loperamide treatment. The concentrations of acetic acid and propionic acid in feces in the loperamide-induced rat with high concentration lactic acid, were significantly higher than that of others. Furthermore, gastrointestinal transit ratio as well as the length and area of intestinal mucosa were significantly increased after treatment with lactic acid bacteria in loperamide-induced rat. Metagenomics DNA analysis indicated that the microorganism homology in cecum was similar between the groups of normal (NOR) and HIG. Our results show that lactic acid bacteria were effective in improving the constipation.

• Food Science of Animal Resources
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• v.31 no.2
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• pp.290-295
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• 2011

This study was conducted to develop an effective probiotic dairy product to normalize the microbial flora in Korean infants. A total of 2,200 colonies were isolated from 25 Korean neonates, and 16S rRNA of 348 isolates was analyzed. Approximately 40% of the lactic-acid producing bacterial isolates were Enterococcus faecalis, and 34.2% of them were strains similar to XR7 in the GenBank database. The fastest growing strain in MRS broth was registered as 91532 by the KACC. The selected strain was freeze-dried and utilized to ferment a milk-containing rice soup, tarakjuk. Microbiological, physico-chemical, and sensory characteristics of the fermented tarakjuk were compared with fermented milk and tarakjuk. E. faecalis KACC 91532 increased from $6.14{\pm}0.19$ to $7.36{\pm}0.13$ Log CFU/mL, and can be useful as a probiotic, as described in the Standards for Functional Health Foods.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.596-603
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• 2008

Lactobacillus acidophilus is a normal inhabitant of the human intestine and its numerous health benefits have been reported. This organism is referred to as a "starter culture". This study was conducted to verify that the production of flavor compounds in fermented milk was obtained using a good probiotic strain of L. acidophilus from breast-fed infant feces. The bitter-tasting amino acids, such as arginine and histidine were produced in larger amounts than other free amino acids when L. acidophilus strains were inoculated in skim milk. The lactic acid was the major acid produced from glucose. L. acidophilus NB 209 was the best producer of lactic acid. This L. acidophilus NB 209 produced higher amounts of acetaldehyde than other L. acidophilus strains. L. acidophilus NB 209 gave higher flavor and taste score of the yogurt produced than other L. acidophilus strains in sensory evaluation. These results indicate that L. acidophilus NB 209 has the potential to be developed as a starter culture for fermented milk products.

• Journal of Dairy Science and Biotechnology
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• v.34 no.4
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• pp.231-237
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• 2016

Kefir is a probiotic food. Probiotics have shown to be beneficial to health, and are currently of great interest to the food industry. Hence, this study was carried out to evaluate the lactase activity of kefir-isolated lactic acid bacteria. Three strains, Lactobacillu kefiri DH5 isolated from the kefir grains and Bifidobacterium animalis subsp. Lactis and Bifidobacteria longum 720, commercial probiotic LAB, were fermented in 10% reconstituted nonfat dry milk suspensions and incubated at $37^{\circ}C$ for 48 h, and then analyzed for various saccarides by HPLC. The results showed that changes in the concentrations of lactose and galactose were significantly decreased and increased, respectively (p<0.05), but all 3 probiotic strains tested in this study showed no increase in glucose concentration during 48 h of incubation. Both DH5 and BL720 showed high lactase activities (p<0.05), whereas BLC exhibited the lowest activity. Additionally, all three lactic acid bacteria showed high tagatose, but did not show high xylose and sedoheptulose. Finally, DH5, a kefir-isolated LAB, may have similar characteristics and properties to typical Bifidobacterium spp. and showed higher lactase activity than commercial Bifidobacterium spp.

• Journal of Life Science
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• v.27 no.2
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• pp.172-179
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• 2017

The fermentation of Panax ginseng can yield many compounds from ginsenosides that have a wide variety of biological functions. Lactic acid bacteria (LAB) strains are capable of converting ginsenosides. The purposes of this study were to: (1) characterize Enterococcus faecium SA5, an isolated LAB from Mongolian mare milk, (2) identify the existence of extracellular ${\beta}$-glucosidase activity in the milk, and (3) ascertain if the ${\beta}$-glucosidase has the capacity of converting ginsenoside in Korean ginseng. The results revealed that E. faecium SA5 was acid-resistant, bile salt-resistant, and has antibiotic activities against 4 pathogenic microorganisms (Salmonella typhimurium KCTC 3216, Listeria monocytogenes KCTC 3710, Bacillus cereus KCTC 1012, Staphylococcus aureus KCTC 1621). In addition, E. faecium SA5 had tolerance against some antibiotics such as colistin, gentamycin and neomycin. It was also found that E. faecium SA5 possessed bile salt hydrolase activity, which could lower blood cholesterol level. When incubated in 10% (w/v) skim milk as a yogurt starter, E. faecium SA5 caused to decrease pH of the medium as well as increase in viable cell counts. Using TLC and HPLC analysis on the samples incubated in MRS broth, our study confirmed that E. faecium SA5 can produce ${\beta}$-glucosidase, which was capable of converting ginsenoside $Rb_1$ into new ginsenosides $Rg_3-s$ and $Rg_3-r$. It was concluded that E. faecium SA5 possessed a potential of probiotic activity, which could be applied to yogurt manufacture as well as ginsenoside conversion in ginseng.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.495-501
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• 1999

Lactobacillus acidophilus KY 2104 was isolated from 41 healthy korean ($2{\sim}35\;age$, 26 man, 15 woman) feces to use as a probiotic lactic acid bacteria for functional foods, fermented milk and pharmaceutical products. L. acidophilus KY 2104 survived in the presence of acid and bile, and inhibited pathogens. It survived almost 100% in pH 3.0 phosphate buffer for 2 hr, and more than $10^4\;cfu/mL$ in pH 2.0 phosphate buffer when inoculated by $10^7\;cfu/mL$. It was also found to grow in MRS medium containing 0.5% oxgall. L. acidophilus KY 2104 exerted inhibitory effect against enteric pathogens such as Escherichia coli, Shigella dysenteriae, Staphylococcus aureus and Salmonella typhimurium, when grown with each in associative cultures for 16 hr. As a result of acute toxicity of L. acidophilus KY 2104 in rats, there was no observation on motality, clinical signs, body weights and gross findings in the oral administration.

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