• Journal of Microbiology and Biotechnology
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• v.8 no.2
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• pp.182-184
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• 1998

PCR was used for quantitative counting of Bifidobacterium spp. in a sample mixed with Lactobacillus acidophilus using two primer sets; one set for universal priming and the other set for Bifidobacterium specific priming. DNA products from two independent PCRs with DNA extracted from the mixed sample were found to be easily distinguishable from each other by agarose gel electrophoresis. The concentrations of PCR products correlated with the total number of bacteria and with the number of Bifidobacterium spp. present in the sample.

• Korean Journal of Poultry Science
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• v.27 no.1
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• pp.31-35
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• 2000

This study was investigated to observe Lactobacillus spp. population of poultry digestive organ, duodenum, ilium, cecum and colon by growing steps and to select of valuable lactobacilli as probiotics. Two strains of male broiler commercial chickens, Hybrid and Ross, were used to evaluate population of Lactobacillus spp. in intestinal tracts. Three strains of Lactobacillus were identified, and bile salts environment. The number of lactovacilli was the lowest in duodenum compared to other intestinal tracts which had similar population. Population of Lactobacillus was maintained constantly regardless growing steps after one week of age. Identification of Lactobacillus from cecum resulted in L.reuteri BC5, L. crispatus BC7, L.reuteri BC9. All strains was depressed in pH 1 and 2, although two strains could survive for one hour at pH 2. And they could survive at pH 4 for 4hours. In bile salts tolerance, L.reuteri BC5, L.crispatus BC7 were maintained for 2 hours, but the growth reduced from 2hours. Growth of L.reuteri BC9 was increased continuously. In conclusion, Lactobacillus of intestinal tracts were established at first week, and maintained constant population. They were influenced on severe acidic condition and bile salts. Cecal Lactobacillus has different growth charcteristics by strains.

• KSBB Journal
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• v.24 no.2
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• pp.182-188
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• 2009

Lactobacillus spp., primary members of probiotics, have significant benefits for health and well-being of human. In this study Lactobacillus strains representing six species (L. paracasei KLB58, L. fermentum MS79 and KLB282, L. plantarum KLB213, L. gasseri KLB238, and L. reuteri KLB270) isolated from Korean adults were electrotransformed with plasmid pNCKH104. To determine optimal electrotransformation conditions, various conditions including cell wall weakening agent, electroporation buffer, electric field strength and time constant were tested for each strain. Overall, high transformation efficiency of approximately 2.5 ${\times}$ $10^3$ ${\sim}$ 5.5 ${\times}$ $10^4$ CFU/${\mu}g$ DNA was obtained where conditions of 0.5 M sucrose electroporation buffer, 1.8 kV pulse voltage and 5 ms time constant were applied. The common conditions developed in this study will make transformation of various Lactobacillus spp. easier than previous procedures.

• KSBB Journal
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• v.15 no.4
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• pp.411-413
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• 2000

A method is described for the rapid and simple isolation of genomic DNA from 3 mL culture of Lactobacillus crispatus KLB46 The isolated DNA using this method was shown to be an excellent substrate for restriction endonclease digestion and PCR. The method is expected to be used in gentic manipulation of L. crispatus KLB46.

• Journal of Food Hygiene and Safety
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• v.22 no.3
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• pp.151-158
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• 2007

Among 68 strains of lactic acid bacteria (LAB) isolated from Dongchimi, a strain K11 was selected due to its bactericidal activity against Escherichia coli O157 The strain K11 was identified as Lactobacillus plantarum, based on physiological and biochemical characteristics. In the late exponential phase, La. plantarum K11 showed maximum bacteriocin activity (12,800 BU/mL) and maintained until the early stationary phase. The bacteriocin activity was completely inactivated by all the proteolytic enzymes such as pepsin, protease, proteinase K, papain, chymotrypsin, and trypsin, but the activity was not affected by catalase, a-amylase, lysozyme, and lipase, suggesting proteinaceous nature of the bacteriocin. Additionally, this activity was not affected in the pH range from 3.0 to 9.0 and under storage conditions like 30 days at -20,4, or $25^{\circ}C$. Although the bacteriocin activity was absolutely lost after 15 min treatment at 121, it was relatively stable at $70^{\circ}C$ for 60 min or $100^{\circ}C$ for 30 min. The activity was disappeared by treatment with acetone, benzene, ethanol, or methanol, but it was not affected by treatment with chloroform or hexane. The antibacterial activity of the bacteriocin was good against some LAB including Lactobacillus spp., Enterococcus spp., and Streptococcus spp., but not against food-borne pathogens such as Bacillus spp., Listeria spp., and Staphylococcus spp. as well as yeasts and molds. Especially, some intestinal bacteria such as Enterobacter aerogenes and E. coli were significantly affected by the bacteriocin of La, plantarum K11. Furthermore, the addition of 640 BU/mL resulted in the complete clearance of E. coli O157 after 10 hr.

• KSBB Journal
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• v.30 no.5
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• pp.239-244
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• 2015

Bacterial vaginosis (BV) is caused by microbial imbalance of the vaginal ecosystem and overgrowth of anaerobic bacteria. The antibiotic treatment often results in very high recurrence of BV because it disturbs the vaginal ecosystem. The high recurrence rates suggest a need for alternative therapeutic methods and probiotics are being recognized as alternative or additional treatment method for BV. The purpose of this study was to investigate how human vaginal isolates of Lactobacillus spp. inhibit the BV-associated pathogen Gardnerella vaginalis. Results show that selected strains significantly reduced the viability of G. vaginalis. Among these selected strains KLB410 and KLB416 were further selected based on acid/bile tolerance and identified through 16S rRNA gene sequencing being Lactobacillus plantarum. Further studies are underway to demonstrate that the selected strain can be applied as potential probiotics for recovering vaginal ecosystem.

• Korean Journal of Organic Agriculture
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• v.13 no.2
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• pp.185-195
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• 2005

Two hundred [(Duroc${\times}$Yorkshire)${\times}$Landrace] pigs were used in a 117-d growth assay (including four growth stages) to determine the effects of dietary supplementation of Lactobacillus reuteri on performance of swine, fecal and rectumal microflora and carcass grade. Pig diet was divided tow types, commercial diet (Control group) and supplemention of 0.1% Lactobacillus reuteri (Treatmental group). There was tend to increased in average daily gain (ADG) and feed efficiency (Feed/gain) in treatmental group than control group during the whole experimental period. The number of Lactobacilius spp. into rectum and feaces and carcass rate tended to increase in treatmental group than control group. Ammonia emission from excreta were decrease by supplemention of 0.1% Lactobacillus reuteri in feed (P<0.05). These results indicated that the dietary Lactobacillus reuteri were effective in performance, increasing of Lactobacilius spp. into rectum and feaces, decreasing ammonia emission from excreta, and it had also effective the carcass rate in swine.

• Pediatric Infection and Vaccine
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• v.24 no.3
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• pp.168-177
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• 2017

Purpose: The purpose of this study was to analyze the clinical features and risk factors of invasive infections caused by Lactobacillus spp. and Saccharomyces spp., components of commercially available probiotics. Methods: We analyzed demographic and clinical data from children ${\leq}18$ years of age with an invasive infection caused by Lactobacillus spp. or Saccharomyces spp. at the Asan Medical Center Children's Hospital from January 1998 to June 2016. Probiotic consumption data were also analyzed. Results: During the study period, a total of 24 episodes of invasive infections were caused by Lactobacillus spp. (n=16) and Saccharomyces cerevisiae (n=8). Along with the increase of probiotic use (755,594 [days/1,000 patient-admission days] in 2001 to 2005, 1,444,066 in 2006 to 2010, and 6,904,736 in 2011 to 2016), the incidence of probiotic-associated invasive infection increased ($R^2=0.70$). The median age of the patients was 1.8 years (range, 2 months to 17 years), and most of them had underlying medical conditions. The 30-day mortality rate was 20.8% (5/24), and 11 (45.8%) of these patients resulted from a severe invasive infection. We determined the risk factors for invasive infection to be: previous intensive care unit stay (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.5 to 6.1] and the presence of a central venous catheter (OR, 2.2; 95% CI, 1.2 to 4.3). Conclusions: Although the probiotic-associated invasive infections rarely occurred in children, the incidence has increased along with probiotic pressure. Judicious use of probiotics is mandatory, especially in young children with underlying medical conditions and continuous surveillance will be needed to minimize the safety concerns.

• Korean journal of food and cookery science
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• v.11 no.2
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• pp.104-107
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• 1995

This study was attempted to simplify the complex steeping mechanism and propose the scientific approach of microorganism. As Enzyme activity showed that as steeping hours increase, the а-amylase activity increased. Most commonly microorganisms in steeping liquid were Corynebacter spp., Candida spp. and Lactobacillus spp. According to results, steeping acidifies the character of glutinous rice, affec-ting the starch's n-amylase and bring about component's changes. As Candide spp. and Lactobaillus spp. of the steeping liquid increase, the character of liquid is acidifying.

• KSBB Journal
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• v.31 no.1
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• pp.85-89
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• 2016

Lactic acid fermentations were conducted using water hyacinth. It is known that the pretreatment and enzyme hydrolysis process optimize the potential of water hyacinth. Lactic acid produced by using lactic acid bacteria. All cells were grown at $37^{\circ}C$ and initial pH 5.5. Lactic acid production was measured by HPLC. All Lactobacillus strains could produce lactic acid from pretreated water hyacinth. The highest lactic acid was achieved when lactic acid fermentation was carried out by L. delbrueckii for D-form and L. helveticus for L-form lactic acid production. The lactic acid concentration was 10.70 g/L by L. delbrueckii and it converted glucose in the medium to lactic acid, almost perfectly. Lactic acid production became higher when fermentation was carried out at a controlled pH 5.5. Lactic acid yield and productivity were 0.52 g/g and 0.19 g/L/h for L. helveticus, while L. delbrueckii was 0.64 g/g and 0.27 g/L/h. This study showed that water hyacinth medium could be alternative medium which can replace the complex and expensive medium for growing Lactobacillus strains in production of lactic acid.