• Journal of Industrial Technology
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• v.28 no.B
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• pp.53-57
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• 2008

From the extensive screening for small cryptic plasmid among about 23 lactic acid bacteria (LAB), 2.4 kb of cryptic plasmid was isolated from Lactobacillus farciminis strain KCTC 3681 and named as pLF24. The plasmid pLF24 was a circular molecule of 2,396 base-pairs in length with a G+C content of 38%. Two protein-coding sequences could be predicted. ORF1 and ORF2 showed homologies to plasmids of gram-positive bacteria. The replication protein coded by ORF2 and the plus origin, were similar to replication regions of other gram-positive bacteria as shown in plasmids such as pLH2, pLS141-1 and pLC2. The nucleotide sequence of pLF24 was deposited into Genbank data base with an accession number of EU429343. The newly isolated plasmid can be used for construction of shuttle vector in Lactobacillus bacteria.

• Toxicological Research
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• v.23 no.1
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• pp.11-17
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• 2007

This study was carried out to investigate the effect of LAB (Lactic acid bacteria: Lactobacillus acidophilus, Bifidobacterium bifidum and Streptococcus thermophilus) on detoxication of damaged liver in carbon tetrachloride ($CCl_4$) and ethanol (25%)-treated rats. Rats had been daily (twice a day) pre-treated with saline (0.5 ml/kg: untreated group), $CCl_4$ (0.5 ml/kg: other groups) for 6 days. At seventh day, after treating rat with $CCl_4$ and then, mixture of LAB ($10^{11}$/0.5 ml: LAB group), saline (0.5 ml/kg: untreated group, $CCl_4$ group), and biphenyl dimethyl dicarboxylate (DDB) (50 mg/kg: DDB group) were treated orally with $CCl_4$ for 8 days. Ethanol is treated as the same manner instead of $CCl_4$. To investigate the hepatoprotective effect, rats treated with $CCl_4$ and ethanol were analyzed with serum GOT and GPT level. The GOT and GPT levels of LAB group was lower than the level of $CCl_4$ and DDB group. Especially, compared with data of $CCl_4$ group, GPT activity showed statistically significant result in the significance level of p < 0.05. The LAB group treated with ethanol also showed lower level of GOT and GPT than the other control groups treated with ethanol. The triglyceride level of serum decreased more in a group treated special materials (DDB and LAB group) than ethanol group. As well, the effect of LAB on the antifatigue has been investigated. The animals (10/group) were divided into 4 groups (untreated group, Carrier group, Red-ginseng group, LAB group). Each group was given carrier (0.9 mg/0.2 ml), red ginseng extract (200 mg/kg), and mixture of LAB ($10^{11}$/0.2 ml). Special materials were given for three weeks. After finishing treating through oral, horizontal wire test, rotarod test, and forced swimming test were performed. The time of resistance to fatigue of the group, fed with mixture of LAB, was longer than the time when mice treated with red-ginseng that the effect was already revealed. The result of this study revealed that LAB could decrease hepatocelluar injury compared with rats treated orally with $CCl_4$ and ethanol, and could also decrease fatigue.

• Journal of Microbiology and Biotechnology
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• v.22 no.8
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• pp.1101-1106
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• 2012

Market fresh makgeolli was stored at different temperatures of $4^{\circ}C$ and $25^{\circ}C$ to assess the change of the microbial diversity according to the storage temperature and period. Yeast counts increased until day 3 of storage and decreased thereafter. General and lactic acid bacterial counts continuously increased during storage. The data indicated that the control of growth of microorganisms, particularly general bacteria and lactic acid bacteria (LAB), is essential. Total acid levels started to decrease in the makgeolli stored at $4^{\circ}C$, and increased from day 6 of storage in the makgeolli stored at $25^{\circ}C$. The increase of total acid in the non-refrigerated condition greatly affected the quality of makgeolli. In both the fresh makgeolli samples stored at $4^{\circ}C$ and $25^{\circ}C$, yeast (Saccharomyces cerevisiae) and molds (Aspergillus tubingensis, Candida glaebosa, and Aspergillus niger) were noted. Denaturing gradient gel electrophoresis (DGGE) band patterns were almost constant regardless of the storage period. As for bacteria, Lactobacillus crustorum, L. brevis, and Microlaena stipoides were found in the makgeolli stored at $4^{\circ}C$, and L. crustorum, Lactobacillus sp., L. plantarum, L. brevis, L. rhamnosus, and L. similis were found in the makgeolli stored at $25^{\circ}C$. In particular, in the makgeolli stored at $25^{\circ}C$, L. crustorum and L. plantarum presented dark bands and were identified as the primary microorganisms that affected spoilage of fresh makgeolli.

• Food Science of Animal Resources
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• v.41 no.6
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• pp.967-982
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• 2021

Probiotics are living microorganisms that, when administered in adequate amounts, provide a health benefit to the host and are considered safe. Most probiotic strains that are beneficial to human health are included in the "Lactic acid bacteria" (LAB) group. The positive effects of probiotic bacteria on the host's health are species-specific and even strain-specific. Therefore, evaluating the probiotic potential of both wild and novel strains is essential. In this study, the probiotic characteristics of Lactobacillus brevis KT38-3 were determined. The strain identification was achieved by 16S rRNA sequencing. API-ZYM test kits were used to determine the enzymatic capacity of the strain. L. brevis KT38-3 was able to survive in conditions with a broad pH range (pH 2-7), range of bile salts (0.3%-1%) and conditions that simulated gastric juice and intestinal juice. The percentage of autoaggregation (59.4%), coaggregation with E. coli O157:H7 (37.4%) and hydrophobicity were determined to be 51.1%, 47.4%, and 52.7%, respectively. L. brevis KT38-3 produced β-galactosidase enzymes and was able ferment lactose. In addition, this strain was capable of producing antimicrobial peptides against the bacteria tested, including methicillin and/or vancomycin-resistant bacteria. The cell-free supernatants of the strain had high antioxidant activities (DPPH: 54.9% and ABTS: 48.7%). Therefore, considering these many essential in vitro probiotic properties, L. brevis KT38-3 has the potential to be used as a probiotic supplement. Supporting these findings with in vivo experiments to evaluate the potential health benefits will be the subject of our future work.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.2
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• pp.125-131
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• 2015

Phenyllactic acid (PLA) which is known as antimicrobial compound can be synthesized through the reduction of phenylpyruvic acid (PPA) by lactate dehydrogenase (LDH) of lactic acid bacteria (LAB). LAB producing PLA was isolated from Korea Kimchi and identified to Lactobacillus plantarum SJ21 by 16 rRNA gene sequence analysis. Cell-free supernatant (CFS) from L. plantarum SJ21 was assessed for both the capability to produce the antimicrobial compound PLA and the antifungal activity against four fungal pathogens (Rhizoctonia solani, Aspergillus oryzae, Botrytis cinerea, and Collectotricum aculatum). PLA concentration was investigated to be 3.23mM in CFS when L. plantarum SJ21 was grown in MRS broth containing 5mM PPA for 16 h. PLA production also could be promoted by the supplement of PPA and phenylalanine in MRS broth, but inhibited by the supplement of 4-hydroxyphenylpyruvic acid and tyrosine as precursors. Antifungal activity demonstrated that all fungal pathogens were sensitive to 5% CFS (v/v) of L. plantarum SJ21 with average growth inhibitions ranging from 27.32% to 69.05% (p<0.005), in which R. solani was the most sensitive to 69.05% and followed by B. cinerea, C. aculatum, and A. oryzae. The minimum inhibitory concentration (MIC) for commercial PLA was also investigated to show the same trend in the range from $0.35mg\;mL^{-1}$ (2.11 mM) to $0.7mg\;mL^{-1}$ (4.21 mM) at pH 4.0. The inhibition ability of CFS against the pathogens was not affected by heating or protease treatment. However, pH modification in CFS to 6.5 caused an extreme reduction in their antifungal activity. These results may indicate that antifungal activities in CFS were caused by acidic compounds like PLA or organic acids rather than proteins or peptides molecules.

• Food Science of Animal Resources
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• v.36 no.5
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• pp.617-625
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• 2016

Pastırma, a dry-cured meat product, is produced from the whole muscle and/or muscles obtained from certain parts of beef and water buffalo carcasses. The purpose of this study was to determine the effects of different levels of sodium nitrite on changes in the physicochemical and microbial quality during the production of pastırma. The changes in residual nitrite, salt, pH, moisture, thiobarbutiric acid reactive substances (TBARS), colour (L*, a*, b*), total aerobic mesophilic bacteria (TAMB), lactic acid bacteria (LAB), Micrococcus/Staphylococcus (M/S), mould-yeast (M-Y), and Enterobacteriaceae counts of pastırma with 0, 50, 100 and 150 ppm sodium nitrite were determined during the production. The nitrite levels and the production stages had significant effects (p<0.01) on residual nitrite, TBARS, pH, salt, and colour values. The TBARS values of the pastırma with nitrite were significantly lower (p<0.05) than the control. The final TAMB, LAB, M/S, and M-Y counts of pastırma with 150 ppm nitrite were significantly (p<0.05) lower than the control. Also, the a* (relative redness) values of control pastırma were significantly lower (p<0.05) than the pastırma with nitrite. The production stages had a significant effect (p<0.01) on the moisture.

• Journal of Dairy Science and Biotechnology
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• v.41 no.4
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• pp.191-202
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• 2023

In this study, lactic acid bacteria (LAB) was isolated from blueberries. The isolated LAB were rod-shaped and gram-positive, as shown using gram staining. In addition, the identified bacteria showed high homology to Lactiplantibacillus argentoratensis. The culture supernatant was isolated from L. argentoratensis and its antibacterial activity against the pathogenic bacteria Salmonella and Escherichia was analyzed. Culture supernatants of L. argentoratensis significantly inhibited the growth of Salmonella. Enteritidis NCCP 16947, Salmonella Typhimurium NCCP 16960, and Salmonella. Thompson NCCP 11704. Interestingly, the higher the concentration of the culture supernatant, the more significant was the antibacterial activity. Additionally, the culture supernatant of L. argentoratensis showed significant antibacterial activity against Escherichia strains. To determine whether the antibacterial substance is stable to heat and pH, the LAB culture supernatant was heat-treated under 65℃ for 30 min, 75℃ for 15 min, 85℃ for 10 min, and 100℃ for 5 min. Measurement of antibacterial activity against pathogenic strains by adding 5% of heat-treated culture medium showed the same antibacterial activity as before heat treatment. However, in a test where the pH of the culture supernatant was adjusted to 7.0 from 3.73, no antibacterial activity was observed.

• Journal of Microbiology and Biotechnology
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• v.32 no.6
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• pp.783-791
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• 2022

Gamma-aminobutyric acid (GABA) improves various physiological illnesses, including diabetes, hypertension, depression, memory lapse, and insomnia in humans. Therefore, interest in the commercial production of GABA is steadily increasing. Lactic acid bacteria (LAB) have widely been reported as a GABA producer and are safe for human consumption. In this study, GABA-producing LAB were preliminarily identified and quantified via GABase assay. The acid and bile tolerance of the L. plantarum FBT215 strain were evaluated. The one-factor-at-a-time (OFAT) strategy was applied to determine the optimal conditions for GABA production using HPLC. Response surface methodology (RSM) with Box-Behnken design was used to predict the optimum GABA production. The strain FBT215 was shown to be acid and bile tolerant. The optimization of GABA production via the OFAT strategy resulted in an average GABA concentration of 1688.65 ± 14.29 ㎍/ml, while it was 1812.16 ± 23.16 ㎍/ml when RSM was applied. In conclusion, this study provides the optimum culture conditions for GABA production by the strain FBT215 and indicates that L. plantarum FBT215 is potentially promising for commercial functional probiotics with health claims.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.5
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• pp.655-661
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• 2011

Two experiments were conducted to investigate the effect of dietary supplementation of Bacillus, Saccharomyces and lactic acid bacteria (LAB) on performance and nutrient digestibility in grower and finisher pigs. In Exp. 1, 80 pigs (32 females and 48 males), $28.7{\pm}0.9\;kg$ body weight (BW), were randomly divided into 4 treatment groups balanced for sex and weight (5 pigs per pen, 4 pens per treatment). They were fed one of four diets: a basal grower (20-50 kg BW) and finisher (>50 kg BW) diet without any addition of probiotic or antibiotic (diet C), the basal diet supplemented with Bacillus subtilis H4 (diet B), diet B supplemented with Saccharomyces boulardi Sb (diet BS) and diet BS supplemented with a LAB complex (diet BSL). The LAB complex consisted of Enterococcus faecium 6H2, Lactobacillus acidophilus C3, Pediococcus pentosaceus D7, and Lactobacillus fermentum NC1. In Exp. 2, 16 male pigs, $29.2{\pm}0.8\;kg$ BW, were kept in individual pens and divided into 4 groups (4 pigs in each group). All 4 groups were given exactly the same growing-period diets (diet C, B, BS and BSL) as in Exp 1. The total faeces and urine were collected during 5 days (day 20-24) to determine nitrogen retention and total tract digestibility. In the growing period, average daily feed intake (ADFI), average daily gain (ADG) and feed conversion ratio (FCR) were not affected by diet B and BS (p>0.05), but ADG increased (+5.9%) (p<0.05) and FCR improved (+5.9%) (p<0.05) on diet BSL compared with the control, although ADFI was not different (p>0.05). Digestibility of crude protein and organic matter was higher (p<0.05) in diet BSL and digestibility of crude fibre was higher (p<0.05) in diet BS and BSL than in diet C. Nitrogen retention was not affected by diet (p>0.05). The faecal LAB counts were increased in grower pigs fed diet BSL (p<0.05) and faecal E. coli counts were decreased in pigs fed diets BS and BSL (p<0.05). In the finishing period, no effects of diet were found in ADFI, ADG, FCR, nutrient digestibility, and nitrogen retention (p>0.05). Faecal LAB and E. coli counts in the finisher pigs were not affected by diet (p>0.05). In conclusion, the current study demonstrates that a mixture of bacteria and yeast has the potential to be used as a probiotic dietary supplement in grower pigs.

• Journal of The Korean Society of Grassland and Forage Science
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• v.18 no.2
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• pp.157-162
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• 1998

This experiment was carried out to investigate the effects of harvesting date and additives on the quality of fall sown oat(Avena sativa L.) silage at the department of animal resources science, college of life resources science, Woosuk University, Wanju &om August, 1997 to March, 1998. The experiment was arranged in a split plot design with three replications. The main plots consisted of the harvesting date such as 15 Oct., 23 Oct. and 2 Nov. and different additives as subplots(control, wheat bran, formic acid, lactic acid bacteria, and wilting). The results otained are summarized as follow : The fiesh and dry matter yield of oat were increased by harvesting date delayed, then fiesh and dry matter yield at 2 Nov. were highest as 36,733 and 7,29Okg/ha, respectively. The dry matter content of oat silage was increased significantly by harvesting date delayed(P< 0.05), and DM content of wheat bran and wilting treatment was high at every harvest date. The DM loss was lower in LAB, formic acid and wheat bran treatment, but on significant difference was found among harvesting date(P< 0.05). Average pH of silage harvested at 23 Oct. was lowest as 4.06, and the quality(CP, NDF, ADF, and IVMDM) of oat silage was decreased by harvesting date delayed. The content of acetic acid was no difference among harvesting date, but butyric acid was decreased and lactic acid was increased at 23 Oct. harvest. The result of this study indicate that oat harvested at booting-heading stage of maturity with wilting wheat bran, and LAB could be recommended as producing high quality of oat silage.