• Asian-Australasian Journal of Animal Sciences
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• v.18 no.1
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• pp.90-95
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• 2005

Lactic acid bacteria were isolated from silage, which produce high level of hydrogen peroxide in cell culture supernatant. The 16S rDNA sequences of the isolate matched perfectly with that of Lactobacillus fermentum (99.9%), examined by a 16S rDNA gene sequence analysis and similarity search using the GenBank database, thus named L. fermentum CS12-1. L. fermentum CS12-1 showed resistance to low pH and bile acid. The production of hydrogen peroxide by L. fermentum CS12-1 was confirmed by catalase treatment and high-performance liquid chromatography. L. fermentum CS12-1 accumulated hydrogen peroxide in culture broth as cells grew, and the highest concentration of hydrogen peroxide reached 3.5 mM at the late stationary growth phase. The cell-free supernatant of L. fermentum CS12-1 both before and after neutralization inhibited the growth of enterotoxigenic Escherichia coli K88 that causes diarrhea in piglets.

• Journal of Microbiology and Biotechnology
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• v.28 no.1
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• pp.32-39
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• 2018

Samples of Laru (a fermentation starter) obtained from the upper part of Borneo Island were analyzed for their lactic acid bacteria (LAB) and fungal diversity using both a culture-independent method (PCR-DGGE) and culture-dependent methods (SDS-PAGE and MALDI-TOF MS). Pediococcus pentosaceus, Lactobacillus brevis, Saccharomycopsis fibuligera, Hyphopichia burtonii, and Kodamaea ohmeri were detected by all three methods. In addition, Weissella cibaria, Weissella paramesenteroides, Leuconostoc citreum, Leuconostoc mesenteroides, Lactococcus lactis, Rhizopus oryzae/Amylomyces rouxii, Mucor indicus, and Candida intermedia were detected by PCR-DGGE. In contrast, Lactobacillus fermentum, Lactobacillus plantarum, Pichia anomala, Candida parapsilosis, and Candida orthopsilosis were detected only by the culture-dependent methods. Our results indicate that the culture-independent method can be used to determine whether multiple laru samples originated from the same manufacturing region; however, using the culture-independent and the two culture-dependent approaches in combination provides a more comprehensive overview of the laru microbiota.

• Korean Journal of Food Science and Technology
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• v.18 no.6
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• pp.492-496
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• 1986

A compound stimulatory to the growth of S. thermophilus CH-1 was isolated from the cell-free filtrate of L. helveticus YM-1 in milk medium. The stimulant was identified as a peptide with a molecular weight of approximately 5000 and exhibited positive ninhydrin reaction. Some kinds of amino acids confirmed as aspartic acid, alanine, valine, glutamic acid, lysine, proline, leucine were rich in the stimulatory peptide hydrolysate. Among them, glutamic acid was most abundant. Judging from bioautographic results, glutamic acid and phenylalanine were expected to exert an important role for the stimulation.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.227-231
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• 2006

Strain NK181 was isolated for probiotic use from jeotkal and based on results of API 50 CHL kit and 16S rDNA sequencing was tentatively named Lactobacillus plantarum NK181. L. plantarum NK181 was highly resistant to artificial gastric juice (pH 2.5) and bile acid and demonstrated strong adherence to Caco-2 cells. In test using API ZYM kit, eight enzymes were produced. Supernatant of L. plantarum NK181 exhibited about 30% 1,1-diphenyl-2-picyryl hedrazyl (DPPH) radical-scavenging activity and reduced cholesterol by 70%. These results demonstrate potential use of L. plantarum NK181 as health-promoting probiotic.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.801-806
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• 2002

A multiplex competitive polymerase chain reaction (PCR) method was developed for the rapid identification and quantification of Leuconostoc mesnteroides and Lactobacillus plantarum populations which are the key microorganisms in kimchi fermentation. The strain-specific primers were designed to selectively amplify the target genes encoding 165 rRNA of L. plantarum and dextransucrase of L. mesenteroides. There was a linear relationship between the band intensity of PCR products and the number of colony forming units of each model organism. The PCR quantification method was compared with a traditional plate-counting method f3r the enumeration of the two lactic acid bacteria in a mixed suspension culture and also applied to a real food system, namely, watery kimchi. The population dynamics of the two model organisms in the mixed culture were reliably predictable by the competitive PCR analysis.

• Journal of Microbiology and Biotechnology
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• v.23 no.3
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• pp.357-363
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• 2013

The identification of bacteriophage proteins on the surface of Lactobacillus rhamnosus Pen was performed by LC-MS/MS analysis. Among the identified proteins, we found a phage-derived major tail protein, two major head proteins, a portal protein, and a host specificity protein. Electron microscopy of a cell surface extract revealed the presence of phage particles in the analyzed samples. The partial sequence of genes encoding the major tail protein for all tested L. rhamnosus strains was determined with specific primers designed in this study. Next, RT-PCR analysis allowed detection of the expression of the major tail protein gene in L. rhamnosus strain Pen at all stages of bacterial growth. The transcription of genes encoding the major tail protein was also proved for other L. rhamnosus strains used in this study. The present work demonstrates the spontanous release of prophage-encoded particles by a commercial probiotic L. rhamnosus strain, which did not significantly affect the bacterial growth of the analyzed strain.

• Journal of Dairy Science and Biotechnology
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• v.41 no.4
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• pp.211-218
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• 2023

This study aimed to identify lactic acid bacteria isolated from eight fermented milk products in Iran. We enumerated Lactobacillus species using De Man-Rogosa-Sharpe (MRS)-maltose and MRS agar with pH adjusted to 5.2, as well as assessment at 37℃ for 48 hr, studied Streptococcus spp. using M17 agar at 43℃ for 24 hr, and assessed Bifidobacterium species using nalidixic acid, paromomycin sulfate, neomycin sulfate, and lithium chloride (BL-NPNL) agar at 37℃ for 48 hr. The total viable Streptococcus spp. cell in fermented milk varied at 4.73-8.83 log CFU/mL. However, Bifidobacterium spp. were not detected in any of the tested samples. Lactobacilli were not detected in four of the eight samples, and viable Lactobacilli cells in the remaining four samples ranged 2.48-3.85 log CFU/mL. The pH of the tested samples ranged 3.53-4.19, and soluble solids (Brix measurement) ranged 7.5%-17.9%. A total of 130 isolates of gram-positive catalase-positive bacteria were characterized at the species level using 16S rRNA sequencing. Sequence analysis identified six species: Streptococcus thermophilus, Lactobacillus delbrueckii subsp. sunkii, Lactobacillus delbrueckii subsp. indicus, Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and Levilactobacillus brevis.

• Microbiology and Biotechnology Letters
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• v.27 no.2
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• pp.113-117
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• 1999

As a basic study for quality improvement of Korean soybean paste and soybean sauce, we investigated on microflora of soybean paste and soybean sauce fermentation. Major Microorganisms were isolated from the sample pastes and sauces, and identified systematically. Selected Microorganisms were identified by MIS whole cell fatty acid analysis by gas chromatography. Identification results showed that Bacillus licheniformis, bacillus pumilis and Bacillus subtilis were dominant in soybean paste and Staphylococcus vitulus, Bacillus subtilis, Bacillus pumilus, and Lactobacillus fermentum were dominant in soybean sauce. It seemed that these Microorganisms played an important role in soybean paste and soybean sauce fermentation and could be used for the further studies such as protease and amylase activities.

• The Journal of the Korean dental association
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• v.9 no.12
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• pp.807-811
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• 1971

This report was concerned with the isolation and identification of bacterial flora in the human dental plaque and the dextransucrase activity of isolated species. The results were obtained as follows: 1. The bacterial flora, isolated from the human dental plaque, was identified as 3 species of resembling streptococci, Streptococcus salivarius strain SD-1, Streptococcus bacilli, Lactobacillus brevis strain SD-3, Lactobacillus acidophilus strain SD-2 and SD-7, resembling Staphylococcus sp, and one species of resembling Leuconostoc mesenteroides strain SD-6. 2. The dextransucrase activites of resembling Streptococcus mitis strain SD-9 and Streptococcus salivarius strain SD-1 were exhibited the highest among the isolated species of human dental plaque.

• Korean Journal of Microbiology
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• v.35 no.4
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• pp.307-314
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• 1999

This study was aimed at the investigation of the possibility of the addition of lactic acid bacteria as "starter"for the preparation of radish juice. Forty strains of lactic acid bacteria were isolated from dongchimi that was fermented by a traditional method. The isolates were assorted into 5groups, Leuconostoc mesenteroides subsp. mesenteroides (J-9), Lacobacillus brevis (J-12), Lactobacillus fermentum (J-7), Lactobacillus sake (J-20), and Lactobacillus plantarum (J-39). Leuconostoc mesenteroides was predominated in the sample of dongchimi with frequency of 52.5%. Each of the strain, which exhibited the beat growth in the species, was selected in the 5species, and investigation of the fermentation characteristcis was carried out. The fermentation were performed for 9 days at 25${\circ}C$ after the inoculation of 0.3% ($10^{6}$ cfu/㎖) to each ultra-filtrated radish juice. The pH, total acidity, content of non-volatile organic acids were examined during the fermentation period. Lactobacillus plantarum showed the highest growth rate and the growth rate of Lactobacillus sake was the lowest. The pH (6.3-6.36) and total acidity (0.09-1.0 %) fo the ultrafiltrated radish juice before fermentation were changed to 3.2-4.3 and 0.65-1.2% after 9days, respectively. The changes of the pH and total acidity were related with the growth of the lactic acid bacteria; the better growth of lactic acid bacteria, the more rapid decrease of pH and increase of the total acidity. when the amount of non-volatile organic acids were estimated during fermentation, citric acid, malic acid, malonic acid, and succinic acid were decreased in all cases. However, the content of lactic acid increased with the progression of fermentation. L. mesenteroides (J-9), L. brevis (J-12) and L. fermentum (J-7) were chosen for the candidates of the starter for the lactic fermentation of radish juice based on the biochemical analysis and sensory evaluation.