• Food Science and Biotechnology
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• v.18 no.2
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• pp.384-389
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• 2009

To isolate lactic acid bacteria having high exopolysaccharides (EPS) production ability, 50 strains were initially isolated from the sourdough. Twenty-one strains formed highly mucoid colonies on the sucrose agar medium, which are indicative of active EPS synthesis. DU-07, DU-10, DU-12, DU-19, and DU-21 produced $11.51{\pm}0.167$, $13.09{\pm}0.193$, $12.72{\pm}0.108$, $11.61{\pm}0.284$, and $13.32{\pm}0.094\;g/L$ EPS, respectively, in MRS medium. The isolated strains, DU-10, DU-12, and DU-21, were identified as Enterococcus flavescens, Enterococcus faecium, and Lactobacillus amylovorus, respectively, by using API 50CHL kit and determining partial sequences of their 16S rDNA. Especially, L. amylovorus DU-21 showed the highest production of EPS, as well as the highest inhibitory activities against pathogenic (p<0.05). Interestingly, the L. amylovorus DU-21 seem to be endemic to sourdough fermentations, as they have not been isolated from other environments.

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1266-1273
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• 2008

Lactic acid bacteria (LAB) with antimicrobial activity and high exopolysaccharide (EPS) production ability isolated from sourdough were studied for their fermentation characteristics as potential new starter cultures. The values of pH, titratable acidity, and viable cell counts were $4.06{\pm}0.009-4.50{\pm}0.015,\;0.787{\pm}0.020%-1.172{\pm}0.018%,\;and\;8.78{\pm}0.08-8.98{\pm}0.06$ log CFU/ml, respectively. In order to select probiotics with a high survival rate in the gut, isolates were tested to assess resistance against the artificial gastric acid and bile juice. Viable LAB counts were significantly (p<0.05) affected by the acidity. At pH 2.0, the total declines in the initial bacterial counts were 4.52$\pm$0.07 log for S. thermophilus St-Body-1, >7.98$\pm$0.03 log for E. flavescens DU-10, >7.95$\pm$0.05 log for E. faecium DU-12, and 3.15$\pm$0.06 log for L. amylovorus DU-21. Among the strains, L. amylovorus DU-21 was the only strain that had bile tolerance under simulated gastrointestinal conditions. In order to improve EPS production by L. amylovorus DU-21, the influence of carbon source was studied. When glucose was used as a carbon source, EPS production dramatically increased to 17.19$\pm$0.28 g/l (p<0.05). The maximum cell growth (10.012$\pm$>0.012 log CFU/ml) and EPS production (18.71$\pm$0.19 g/l) were achieved when 15 g/l of glucose was employed as the carbon source.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.5
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• pp.648-657
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• 2014

Silage making has become a significant method of forage conservation worldwide. To determine how tomato pomace (TP) may be used effectively as animal feed, it was ensilaged for 90 days and microbiology counts, fermentation characteristics and chemical composition of tomato pomace silage (TPS) were evaluated at the 30th, 60th, and 90th days, respectively. In addition, 103 lactic acid bacteria were isolated from TPS. Based on the phenotypic and chemotaxonomic characteristics, 16S rDNA sequence and carbohydrate fermentation tests, the isolates were identified as 17 species namely: Lactobacillus coryniformis subsp. torquens (0.97%), Lactobacillus pontis (0.97%), Lactobacillus hilgardii (0.97%), Lactobacillus pantheris (0.97%), Lactobacillus amylovorus (1.9%), Lactobacillus panis (1.9%), Lactobacillus vaginalis (1.9%), Lactobacillus rapi (1.9%), Lactobacillus buchneri (2.9%), Lactobacillus parafarraginis (2.9%), Lactobacillus helveticus (3.9%), Lactobacillus camelliae (3.9%), Lactobacillus fermentum (5.8%), Lactobacillus manihotivorans (6.8%), Lactobacillus plantarum (10.7%), Lactobacillus harbinensis (16.5%) and Lactobacillus paracasei subsp. paracasei (35.0%). This study has shown that TP can be well preserved for 90 days by ensilaging and that TPS is not only rich in essential nutrients, but that physiological and biochemical properties of the isolates could provide a platform for future design of lactic acid bacteria (LAB) inoculants aimed at improving the fermentation quality of silage.

• Korean Journal of Poultry Science
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• v.27 no.3
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• pp.235-242
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• 2000

A feeding trial was carried out effect of supplemental Lactobacillus on productivity, egg quality and intestinal microflora in 320 21 weeks - old laying hens for 12 week. Supplemented Lactobacillus strains were Lactobacillus amylovorus LLA7(LA), Lactobacillus crispatus LLA9(LC) and Lactobacillus vaginalis LLA11(LV). Three strains mixed to basal diet which containing 2,800㎉/kg ME, 16% CP with none, LA, LC, LV, LA+LC, LA+LV, LC+LV and LC+LC+LV. Supplemental level was 10(sup)7 cfu/g diet. Egg production was tended to increase with adding Lactobacilus, but not difference significantly. Average egg weight was heavier in adding Lactobacillrs compared to the none, and heaviest in LA+LV, LC+LV(P〈0.05). In periodic observation, the gap of egg weight with adding Lactobacillus or not was severe persisting laying periods. The diet containg MC or LV was better than LA, which means the difference by Lactobacillus strains for egg weight. Daily egg mass also increased in adding Lactobacillus about 1.1 to 2.3 g/hen, but not difference significantly. Feed intake and feed conversion were not difference regardless Lactobacillus strains and laying periods. Haugh unit improved with adding Lactobacillus. Cecal Lactobacillus spp. was increased with adding Lactobacillus(P〈0.05), didn't observed E. coli depression. In summary, supplemental Lactobacillus could improve for egg production, egg weight, egg mass and egg white. And those of effect expect much beneficial with mixing Lactobacillus which established well as single strain.

• Korean Journal of Poultry Science
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• v.27 no.3
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• pp.227-233
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• 2000

Preset study was carried out to evaluate characteristics of lactic acid producing bacteria(LAB) in hen's cecum as probiotics value. Distribution of LAB in intestinal tracts was investigated using 5∼25 weeks - old hens. So, 12 strains to LAB with different morphology were isolated purely. Acid tolerance of LAB tested at pH 1, 2, 3, and 4, and bile resistant also tested at 0, 0.3% and 0.5% bile salt concentration. Growth pattern of LAB observed to 60h. All strains of cecal LAB couldn't survive at pH 1, and decreased linearly survival colony after incubation at pH 2 although some strains could survive for 2h. Most of LAB maintained constant number at pH 3 and 4. The bacterial action could increase linearly at 0% bile salt concentration in all of tested strains. However, only one strain could multiply at 0.3% bile salt, others were influenced by bile salt. That tendency was similar at 0.5% bile salt. Growth was peaked at 12 to 18 h after innoculation. After peak, the decreasing pattern of colony was different to strains which some strains decreased rapidly or maintained for long time. The LAB of hen's cecum was similar to intolerance acidity, but different to resistant to bile salt and growth pattern by strain. So, we choose three strains which have probiocs value, and identified as Lactobacillus amylovorus LLA7, Lactobacillus crispatus LLA9 and Lactobacillus vaginalis LLA11.

• Journal of Dairy Science and Biotechnology
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• v.31 no.2
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• pp.153-159
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• 2013

Lactic acid bacteria are microorganisms that are closely associated with human and/or animal environments, and are categorized as generally recognized as safe (GRAS) organisms due to their ubiquitous appearance in foods and their contribution to the healthy microflora of mucosal surfaces. This study was performed to isolate and identify lactic acid bacteria with antagonistic effects against food-borne pathogens. A total of 3,000 acid-producing bacteria were isolated from infant feces, cattle feces, goat feces, dog feces, pig feces, vaginal tracts, vegetables, fruits, Kimchi, Jeotgal, fermented sausages, raw milk, cheese, yogurt, Cheonggukjang, Meju, and Makgeolli cultured on MRS agar with 0.05% bromocresol purple. For the isolation of bacteriocin-producing bacteria, the diameter of the clear zone was measured on MRS agar plates. Twenty-six isolates exhibited strong antibacterial activity against indicator strains such as Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica serovar Enteritidis. Lactic acid bacteria were identified as Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Lactobacillus acidophilus, Lactobacillus amylovorus, Lactobacillus curvatus, Lactobacillus plantarum, and Pediococcus acidilactici by 16S rDNA gene sequence analysis. The results of this study suggest that the isolates could be used as potential probiotic starters for functional food applications.

• Food Engineering Progress
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• v.14 no.3
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• pp.208-216
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• 2010

Lab scale experiments were conducted in order to assess the applicability of $CaCO_{3}$-alginate beads as neutralizer for the high cell density cultivation and prepare the direct vat inoculation cultures of isolated sourdough lactic acid bacteria. With increasing the amount of bead and decreasing the diameter of bead in acidic solution, the neutralizing effect of $CaCO_{3}$-alginate bead became higher. In batch process with $CaCO_{3}$-alginate beads, Lactobacillus amylovorus DU-21 isolated from sourdough showed the highest viable cell counts and optical density in MRS broth. The values of viable cell counts and optical density were 9.996 log CFU/mL and 3.97, respectively. Experiments on the conditions which increase viability during lyophilization were carried out and the following results were obtained; 15% glycerol revealed the high cryoprotective effect on the concentrated cultures during lyophilization among the two cryoprotective agents. Consequently, $CaCO_{3}$-alginate beads and 15% glycerol were found to be useful not only to cultivate Lactobacillus amylovorus DU-21 but also to preserve strain.

• Food Engineering Progress
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• v.15 no.4
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• pp.346-354
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• 2011

This study was carried out to fortify the antimicrobial activity of yoghurt by adding liquorice extract to it. The liquorice extracts (1 mg/mL) showed relatively high antibacterial activity against H. pylori KCCM 40449 (p < 0.05). The solvent liquorice extracts of minimal inhibitory concentrations (MIC) against H. pylori KCCM 40449 were 25- 100 ${\mu}g$/mL. Lactobacillus amylovorus DU-21 with high EPS production ability were inoulated to milk after the addition of different amounts of liquorice extracts (0.0%, 0.05%, 0.1% and 0.2%). The physico-chemical characteristics of yoghurts added with liquorice extracts were examined. The initial pH, titratable acidity, viscosity and viable cell counts of the yoghurt added liquorice extracts were 3.41-3.51, 1.021-1.091%, 1,686-1,930 cp and 9.41-9.38 Log CFU/mL, respectively. The viscosity and syneresis of yoghurt were better than that of the control. Antimicrobial activity against H. pylori KCCM 40449 increased with increasing addition of liquorice extract. However, the sensory score of yoghurt added with different amounts of liquorice extracts was lower than that of the control (p < 0.05). As a result of the sensory evaluations, the flavor, taste, texture, color and overall acceptability of the yoghurt with 0.05% liquorice extract were found to be much better than those of the other groups (p < 0.05). Overall, the optimal amount of liquorice extract added in the manufacture of yoghurt was 0.05% of the total weight. Further studies on increment of antimicrobial activity and palatability of liquorice extract added yoghurt are necessary.