• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.2
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• pp.151-157
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• 2015

This study was conducted to evaluate the effect of lactic acid bacterial fermentation on the antioxidant and anti-inflammatory activity of an edible brown alga, Eisenia bicyclis. Lactic acid bacteria were inoculated into and cultivated in E. bicyclis water extract. The antioxidant activity of the extract was assayed before and following fermentation. Antioxidant activity was determined by assaying the levels of radical scavenging activity against 2,2'-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical and alkyl radical. The lactic acid bacterial fermentation of E. bicyclis extract resulted in enhanced antioxidant activity. The greatest enhancement of antioxidant activity was seen in the DPPH radical scavenging assay, in which E. bicyclis extract was fermented by Pediococcus pentosaceus MBP-34 strain for 12 h. This fermented extract also exhibited higher inhibitory activity (96.66%) on nitric oxide production compared with other lactic acid bacterial fermented extracts or raw extract (189.60%). In conclusion, fermentation by bacterial strain is an attractive strategy for developing value-added food ingredients.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1059-1064
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• 1998

Fermented beverage using lactic acid bacteria isolated from kimchi was investigated. Lactic acid bacteria KL 1, KD 6, KL 4 strains from kimchi, or obtained Lactobacillus acidophilus, Lactobacillus plantarum, Leuconostoc mesenteroides with and without yeast(Saccharomyces cerevisiae) were inoculated in fruit vegetable juice for single and mixed culture fermentation. During the fermentation by bacterial strain and yeast for 1~3 days at 30oC, various fermentation behaviors were observed. The growth rate of mixed culture of KL 1 and yeast was higher than that of single culture by KL 1 alone during the fermentation. The amount of organic acid produced by the mixed culture fermentation of KL 1 and yeast was 0.82%(3 day) or 0.58%(1 day) and with the final pH of 3.3(3 day) or 4.2(1 day). These mixed culture systems of isolated strains or other bacterial strains had almost similar results of growth rate and acid production. Among several bacterial strains, KL 1 was suitable for the mixed culture fermentation with yeast in terms of desirable fermentation behavior and organoleptical quality. The selected strain, KL 1 was identified as Leuconostoc spp. through the series of tests on carbohydrate fermentation and biochemical characteristics.

• Journal of Microbiology and Biotechnology
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• v.27 no.3
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• pp.500-506
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• 2017

To investigate the potential applications of bacterial heme, aminolevulinic acid synthase (HemA) was expressed in a Corynebacterium glutamicum HA strain that had been adaptively evolved against oxidative stress. The red pigment from the constructed strain was extracted and it exhibited the typical heme absorbance at 408 nm from the spectrum. To investigate the potential of this strain as an iron additive for swine, a prototype feed additive was manufactured in pilot scale by culturing the strain in a 5 ton fermenter followed by spray-drying the biomass with flour as an excipient (biomass: flour = 1:10 (w/w)). The 10% prototype additive along with regular feed was supplied to a pig, resulting in a 1.1 kg greater increase in weight gain with no diarrhea in 3 weeks as compared with that in a control pig that was fed an additive containing only flour. To verify if C. glutamicum-synthesized heme is a potential electron carrier, lactic acid bacteria were cultured under aerobic conditions with the extracted heme. The biomasses of the aerobically grown Lactococcus lactis, Lactobacillus rhamosus, and Lactobacillus casei were 97%, 15%, and 4% greater, respectively, than those under fermentative growth conditions. As a potential preservative, cultures of the four strains of lactic acid bacteria were stored at $4^{\circ}C$ with the extracted heme and living lactic acid bacterial cells were counted. There were more L. lactis and L. plantarum live cells when stored with heme, whereas L. rhamosus and L. casei showed no significant differences in live-cell numbers. The potential uses of the heme from C. glutamicum are further discussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.552-558
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• 2013

This study was performed to determine effects of the supplementation of Kimchi lactic acid bacterial culture in extruded pellets (EP) on the growth, body composition, blood chemistry and immune response of olive flounder Paralichthys olivaceus. Four hundred eighty individuals averaging 16.1 g were randomly distributed into 12, 180 L flow-through tanks (forty fish per tank). Four concentrations of Kimchi lactic acid bacterial culture (KL) were prepared: Control (0%), 0.1%, 0.2% and 0.5%. Three concentrations (0.1%, 0.2% and 0.5%) of Kimchi lactic acid bacterial culture were each diluted to 10% of EP weight and then fully absorbed by EP for 10 minutes. Each diet was fed to triplicate groups of fish. Fish were hand-fed to apparent satiation twice a day for 8 weeks. At the end of the 8-week feeding trial, the plasma lysozyme and bacterial activities of fish were determined. In addition, the cumulative mortality of fish was monitored for 8 days after their artificial infection with Edwardsiella tarda. The weight gain, specific growth rate, feed efficiency ratio, protein efficiency ratio, protein retention, hepatosomatic index and condition factor of fish were not affected by dietary supplementation with KL. None of the proximate composition, plasma parameters, lysozyme or bactericidal activities of fish was affected by dietary supplementation with KL. However, the cumulative mortalities of fish fed EP containing 0.1% and 0.5% Kimchi lactic acid bacterial culture were relatively low compared to that of fish fed the control diet. In conclusion, dietary supplementation with KL did not effectively improve growth, feed utilization, body composition, plasma chemistry, lysozyme, bactericidal activities or immune response of olive flounder after E. tarda infection under these experimental conditions.

• Ocean Science Journal
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• v.41 no.2
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• pp.113-119
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• 2006

Seventeen lactic acid bacterial strains (LAB) were isolated using MRS agar medium from Jeotgal, a Korean fermented food, purchased at the Jukdo market of Pohang. To identify the strains isolated, they were tested by examining their cell morphologies, gram-staining, catalase activity, arginine hydrolase activity, D-L lactate form and carbohydrate fermentation. According to the phenotypic characteristics, three strains were tentatively identified as Lactobacillus spp., ten were Enterococcus spp. (or Streptococcus spp., or Pediococcus spp.) and the rest were Leuconostoc spp. (or Weissella spp.). Five strains among 17 were chosen by preliminary bacteriocin activity test. Four bacterial strains which inhibited both indicator microorganisms were identified by 16S rRNA sequencing. The results are as follows; Leuconostoc mesenteroides (HK 4), Leuconostoc mesenteroides (HK 5), Leuconostoc mesenteroides(HK 11), Streptococcus salivarius(HK 8). In order to check LAB which are showing a high survival rate in gut, we investigated three strains inhibiting both indicator microorganisms in artificial gastric acid and bile juice -all except HK8. The three strains mentioned above grew in extreme low acid conditions.

• Animal Bioscience
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• v.35 no.8
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• pp.1162-1173
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• 2022

Objective: This study aimed to investigate the fermentation profiles, bacterial community and predicted metabolic characteristics of Sudangrass (Sorghum sudanense Stapf.) during ensiling. Methods: First-cutting Sudangrass was harvested at the vegetative stage and ensiled in laboratory-scale silos (1 L capacity). Triplicate silos were sampled after 1, 3, 7, 15, 30, and 60 days of ensiling, respectively. The bacterial communities on day 3 and 60 were assessed through high-throughput sequencing technology, and 16S rRNA-gene predicted functional profiles were analyzed according to the Kyoto encyclopedia of genes and genomes using Tax4Fun. Results: The Sudangrass silages showed good fermentation quality, indicated by higher lactic acid contents, and lower pH, butyric acid and ammonia nitrogen contents. The dominant genus Lactococcus on day 3 was replaced by Lactobacillus on day 60. The metabolism of amino acid, energy, cofactors and vitamins was restricted, and metabolism of nucleotide and carbohydrate was promoted after ensiling. The 1-phosphofructokinase and pyruvate kinase of bacterial community seemed to play important roles in stimulating the lactic acid fermentation, and the promotion of arginine deiminase could help lactic acid bacteria to tolerate the acidic environment. Conclusion: High-throughput sequencing technology combined with 16S rRNA gene-predicted functional analyses revealed the differences during the early and late stages of Sudangrass ensiling not only for distinct bacterial community but also for specific functional metabolites. The results could provide a comprehensive insight into bacterial community and metabolic characteristics to further improve the silage quality.

• Journal of Microbiology and Biotechnology
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• v.24 no.11
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• pp.1510-1515
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• 2014

Lysobacter capsici YS1215 isolated from soil previously showed nematicidal potential for biological control of the root-knot nematode. In this study, lactic acid, a nematicidal compound, was isolated from culture filtrate of YS1215, and its ovicidal activity was investigated. Purification and identification of lactic acid were performed by a series of column chromatographies and identified by $^1H$ and $^{13}C$ NMR spectra and GC-MS analysis. Our results showed that bacterial culture filtrate containing lactic acid significantly inhibited egg hatching. The lowest egg hatch rate (5.9%) was found at a high concentration ($25 {\mu}l/ml$) of lactic acid at 5 days after incubation, followed by 20 (15.2%), 15 (23.7%), 10 (29.8%), and $5(36.4%){\mu}l/ml$, while egg hatching in the control (sterile distilled water) was 44.5%. This is the first report of lactic acid as an ovicidal compound, and it may be considered as an alternative of chemical pesticide against root-knot nematodes.

• 한국유가공학회:학술대회논문집
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• 2002.04a
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• pp.45-55
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• 2002

Recent developments in the application of molecular biology to food grade lactic acid bacteria (LAB) have shown that it could be feasible to engineer metabolic pathways to either enhance specific metabolic fluxes or to divert metabolites for the production of different or new end products. This engineering requires detailed knowledge of enzymes involved in metabolism and regulation within the targeted organism but little works have been done in this area. During biochemical and molecular characterisation of lactic bacterial enzymes, some of probiotic Lactobacillus and Bifidobacterium species were found to be very useful for food, nutraceutical and pharmaceutical industries. The enzymes are usually intracellular and the yields are very low to be useful for industrial applications. Among many enzymes and proteins of lactic bacteria studied, some of our gene cloning achievements have contributed to overproduction of lactic bacterial enzymes such as peptidases, esterases, lactases, bile salt hydrolases and linoleate isomerases for foods and nutraceuticals.

• The Korean Journal of Food And Nutrition
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• v.12 no.1
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• pp.69-76
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• 1999

In order to screen lactic acid bacterial starter having high antibacterial activity and giving good flavor in Dongchmi for Naengmyon antibacterial activity and acid producing ability of 24 strains of Kimchi lactic acid bacteria were tested. Among 24 strains tested Leuconostoc mesenteroides subsp. mesenteroides C16, Leu. paramesenteroides C18 Lactobacillus bavaricus B01, B06, C19, C32 Lac. homohiochii B21 and B22 showed high antibacterial activity and their antibacterial activities were more active against Listeria monocytogenes and Staphylococcus aureus than against Escherichia coli and Salmonella typhimurium. The odors of Dongchimi-juices fermented with Leu. mesenteroides or Leu. paramesenteroides were more favorable than those with Lac. bavaricus or Lac. homohiochii. But the odors of Naengmyon-broths which were made with each Dongchimi-juice were not significantly different each other. In consideration of antibacterial ac-tivity and flavor of Dongchimi-juice two strains of lactic acid bacteria Lac. homohiochii B21 and Leu. mes-enteroides subsp. mesenteroides C16 were finally screened out as Dongchimi starters.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.227-232
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• 2014

In this study, Gluconacetobacter sp. gel_SEA623-2 isolated from citrus that produces bacterial cellulose was used to examine the effect of initial concentration of acetic acid and mixed culture inoculated with Lactobacillus plantarum KCCM 80077 on productivity of bacterial cellulose. In mixed culture added with 0.5% acetic acid, the viable cell count increased from $2.4{\times}10^6CFU/ml$ to $1.1{\times}10^7CFU/ml$ after 14 days of culture, and total acidity was about 0.3% higher than single culture added with 0.5% acetic acid, which implies that additional lactic acid was produced by L. plantarum KCCM 80077. In single culture, although bacterial cellulose productivity was higher when the initial concentrations of acetic acid were 0.0% and 0.5%, than when it was 1.0%, there was no significant difference. However, in mixed culture, adding 0.5% acetic acid resulted in dry weight of $37.83{\pm}6.81g/L$ and thickness of $10.33{\pm}0.58mm$, showing a significant difference from that of single culture added with 1% acetic acid, $28.40{\pm}1.23g/L$ and $7.50{\pm}0.50mm$ (P<0.05).