• Korean Journal of Microbiology
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• v.45 no.4
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• pp.391-396
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• 2009

This study was carried out to investigate the changes in yeast cell number, organic acid and total acid during the fermentation and distribution processes for enhancement of preservation of Makgeolli. Organic acids, including lactic acid, succinic acid, malic acid and citric acid, were increased with fermentation time, while oxalic acid, phosphoric acid and acetic acid were not detected, respectively. Production of organic acids leaded to pH reduction in Makgeolli. In case of Makgeolli kept at $4^{\circ}C$, there was no change in organic acids until 20 days. On the other hand, when observing the change in organic acid of Makgeolli kept at $25^{\circ}C$, concentration of lactic acid was decreased, while citric acid was not detected from the beginning of storage. However, acetic acid was detected from 10th day and rapidly increased at the 25th day. Therefore, it is suggested that the current expiration date (10 days in a cooler) could be extended.

• Journal of Food Hygiene and Safety
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• v.10 no.2
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• pp.65-71
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• 1995

Bacteriocins from lactic acid bacteria have attracted much attention in recent years because of their useful worth in increasing safety and extending shelf life of foods. These substances show an inhibitory effect against some food spoilage bacteria and food-borne pathogens. The inhibitory effect fo the bacteriocin produces by lactic acid bacteria against Listeria monocytogenes(L. monocytogenes) was examined in this study. The culture supernatants of 5 kinds of bacteria among the 10 kinds of testes lactic acid bacteria had the inhibitory activity against Listeria sp., various Gram positive and Gram negative bacteria. Bacteriocin produced by Lactobacillus plantarum(Lact. plantarum) LMG 7945 was the most active toward L. monocytogenes. Bacteriocin production of the Lact. plantarum LMG 7945 cultured on MRS broth was increased late logarithmic phase over early stationary phase. This bacteriocin was stable at heat treatment and acidic pH relatively; The activity was retained after heating at 121$^{\circ}C$ for 15min and was active in the pH range of 2~4 but was lost above pH 5.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.905-908
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• 2006

The purpose of this research was to study the effects of kefir whey (kefir whey, peptides, lactic acid) on skin care properties including skin lightening effect and acne treatment. The final aim was to develop a new cosmetic product and enhance the value of dairy products. The results of skin lightening tests showed that all three kefir whey components (kefir whey, peptides and lactic acid) had inhibitory ability against melanin synthesis. Furthermore, copper chelating analysis demonstrated that both kefir whey and kefir whey peptides could chelate the copper in tyrosinase, which might explain the mechanism of inhibition. The ability for acne treatment indicated that lactic acid level higher than 60 mg/ml could inhibit the growth of Propionibacterium acne, whereas no inhibition was found with other components.

• Food Science and Biotechnology
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• v.16 no.4
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• pp.605-609
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• 2007

The effects of lactic acid fermented yam yogurt (Yam/YG) on colon mucosal tissue were investigated in a loperamide-induced constipation rat models. Sprague-Dawley rats were fed for 6 weeks with 3 types of diets (normal, supplemented with lactic acid bacteria, and supplemented with Yam/YG), and were then administered loperamide intraperitoneally twice daily for 5 days. Administration of loperamide decreased fecal excretion and the moisture content of feces with increasing of numbers of pellets in the colon. On the histopathologic findings from hematoxylin and eosin (H& E) and alcian blue stainings, supplementation with Yam/YG resulted in the recovery of depleted goblet cells and mucin, and increased the numbers of Ki-67 positive cells, indicating restoration of colonic mucosa through cell proliferation and crypt regeneration against damages observed in crypt epithelial cells of loperamide-induced rats. These results indicate that Yam/YG improves evacuation and mucus production in the gastrointestinal tracts of constipated-induced rats.

• KSBB Journal
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• v.26 no.6
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• pp.543-551
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• 2011

Bacterial antibiotic resistance is a real and growing problem for both Gram positive and Gram negative bacterial pathogens in the hospital setting. Among Gram negative bacteria, the ubiquitous bacterium Pseudomonas aeruginosa is a particular concern in immunocompromised and burn patients. The present study evaluated antibacterial activity and efficacy of a Korean herbal medicine against eight multi-drug resistant clinical isolates of P. aeruginosa (0225, 0254, 0347, 0826, 1113, 1378, 1731, and 2492) isolated at Daegu Catholic University Hospital. Methanol extracts of Galla rhois (5 and 10 mg/mL) displayed inhibition diameters for isolate 2492 of 10 and 12 mm, respectively, in a conventional disc diffusion assay. In seven kinds of Korean herbal medicines, increased inhibitory power of Lonicera japonica, Gardenia jasminoides, Galla rhois, and Scultellaria baicalensis was evident with the fermentation of six kinds of lactic acid bacteria. Three lactic acid bacteria (Lactobacillus plantarum subsp. plantarum KCTC 3108, L. casei KCTC 3109, and L. fermentum KCTC 3112) were identified as excellent strains for the production of antibacterial materials. In the six Korean herbal medicine extracts, strong inhibitory activity of fermented Forsythia suspensa, Glycyrrhizae radix, Lycium chinense, Platycodon grum, and Schizandra chinensis with five kinds of lactic acid bacteria was evident for seven multi-drug resistant P. aeruginosa isolates.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.12
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• pp.1741-1745
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• 2004

Administration of milk and fermented milks produced from indigenous dadih lactic acid bacteria on serum lipids and bile acids, fecal bile acids and microflora was estimated in hypercholesterolemic rats. Anaerobic lactic acid bacteria decreased and coliforms increased in the feces of the control group; however, the number of fecal lactic acid bacteria remained unchanged when rats were administered milk and fermented milks. Only fermented milk made from Lc. lactis subsp. lactis IS-10285 significantly reduced serum total cholesterol, LDL cholesterol and total bile acids. Milk and fermented milks did not influence the HDL cholesterol. Triglyceride and phospholipid levels were significantly lower in the rats fed fermented milk of Lc. lactis subsp. lactis IS-10285 than rats fed milk and fermented milk of Lc. lactis subsp. lactis IS-29862, but not significantly different from the control group. Hypocholesterolemic effect of Lc. lactis subsp. lactis IS-10285 was attributed to its ability to suppress the reabsorption of bile acids into the enterohepatic circulation and to enhance the excretion of bile acids in feces of hypercholesterolemic rats.

• Journal of Food Hygiene and Safety
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• v.5 no.1
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• pp.35-40
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• 1990

As a link in the studies on the extracellular polysaccharide by lactic acid bacteria, the experiment was conducted to investigate the viscosity variations and rheological properties of 10% reconstituted skim milk and 12% reconstituted whole milk, respectively. 1. 10% reconstituted skim milk cultured by Str. thrennophilus 510 showed strong flow property of pseudoplastic fluid depending upon the production of exopolysaccharide. And the viscosity reached the highest value within 14% concentration. 2. 12% reconstituted whole milk cultured by lactic acid bacteria indicated flow property of pseudoplastic fluid. But there was a big difference in the viscosity as compared with 10% skim milk. 3. The maximum consistency index (k) and the minimum flow behavior index (n) of the fermented milk by Str. thermophilus 510 were 43 and 0.09, respectively. They were 35 and 0.09, in case of Lb. bulgaricus.

• Applied Biological Chemistry
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• v.30 no.1
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• pp.17-23
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• 1987

Soy milk prepared from soy protein concentrate was fermented with each of the following lactic acid bacteria: Lactobacillus acidophilus KFCC 12731, L. acidophilus AKU 1122, L. bulgaricus, L. casei, Leuconostoc mesenteroides and Streptococcus lactis. The effects of methionine supple mented to soy milk on the growth and acid production by each organism. were investigated. L-methionine reduced the acid production by two strains of L. acidophilus while it had no apparent. effects on the other test cultures. The inhibitory effects of L-methionine on L. acidophilus KFCC 12731 was greater than on L. acidophilus AKU 1122. The acid production by L. acidophilus KFCC 12731 was also reduced substantially by DL-methionine supplemented to soy milk while it was not affected by D-methionine. Supplementation of L-cysteine to soy milk resulted in slight reduction of acid production by L. acido philus KFCC 12731.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.3
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• pp.394-400
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• 2004

To investigate the efficacy of alternatives to antibiotics, the present study was conducted to compare the effects of antibiotic, lactic acid, a blend of commercial essential oils (EOs) and EOs in combination with lactic acid on growth performance and the functional activity of the gut in broiler chickens. A total of 168 broiler chickens were given the basal diet supplemented with 10 ppm colistin (T1), 0.1% lactic acid (T2), 25 ppm EOs (T3), 25 ppm EOs+0.1% lactic acid (T4), 50 ppm EOs (T5) or 50 ppm EOs+0.1% lactic acid (T6) in the period 3 to 35 days of age. As a result, the broiler chickens assigned to T4 group throughout the experimental period had apparently (p<0.05) greater body weight and total gain than these assigned to T1, T2, T3 and T5 groups. However, there was no difference in growth performance among the birds fed the diets supplemented with antibiotic (T1), lactic acid (T2) and EOs (T3 and T5) alone. The weights of digestive organs and the number of lactobacilli and E. coli in the lower ileum were not affected by dietary treatments. Total trypsin activity was significantly (p<0.05) greater in T4 than T1, T2, T3 and T5 groups. Total and specific pancreatic $\alpha$-amylase activities were significantly (p<0.05) enhanced in the broiler chickens fed T4 diet compared with these fed T1, T2 and T3 diets. However, there were no differences in growth performance and digestive enzyme activities including pancreatic trypsin and $\alpha$-amylase between T4 and T6 groups fed the diets supplemented with either low or high EOs levels in combination of lactic acid. In conclusion, a blend of commercial EOs combined with lactic acid showed significant increases in digestive enzyme activities of the pancreas and intestinal mucosa, leading to increase in growth performance.

• Microbiology and Biotechnology Letters
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• v.49 no.4
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• pp.559-565
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• 2021

This study aimed to optimize gamma-aminobutyric acid (GABA) production by employing five strains of lactic acid bacteria (LAB) that were capable of high cell growth and GABA production using a modified synthetic medium. GABA production in the strains was qualitatively confirmed via detection of colored spots using thin layer chromatography. Lactobacillus plantarum SGL058 and Lactococcus lactis SGL027 were selected as the suitable strains for GABA production. The conditions of the carbon and nitrogen sources were determined as 5 g/l glucose (L. plantarum SGL058), 5 g/l lactose (L. lactis SGL027), 10 g/l yeast extract (L. plantarum SGL058), and 20 g/l yeast extract (L. lactis SGL027) for GABA production. The cell growth, monitored by optical density at 600 nm, was 5.93 for L. plantarum SGL058. This value was higher than the 3.04 produced by L. lactis SGL027 at 36 h using a 5-L fermenter. The highest concentration of GABA produced was 546.7 ㎍/ml by L. plantarum SGL058 and 404.6 ㎍/ml by L. lactis SGL027, representing a GABA conversion efficiency of (%, w/w) of 4.0% and 3.4%, respectively. The fermentation profiles of L. plantarum SGL058 and L. lactis SGL027 provide a basis for the utilization of LAB in GABA production using a basal synthetic medium.