• Journal of Dairy Science and Biotechnology
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• v.31 no.1
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• pp.51-58
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• 2013

Emerging studies suggest that vegetables or fruit juices deemed to be potential alternative base medium for lactic acid bacteria fermentation. Until now, limited studies have been carried out to evaluate such applications. Thus, the objective of present study is that lactic acid bacteria were evaluated for their viability at low pH, growth during storage at low temperature, and $CO_2$ formation. Furthermore, the effects of grapefruit extract with respect to cell viability, sensory ability, and organic acid production were evaluated for these strains. The probiotic properties of the strains, including acid tolerance, bile tolerance, and adhesion to human intestinal epithelial cells (HT-29 cells), prebiotic characteristics, and safety features were examined. All strains survived in MRS medium broth adjusted to pH 3.8, at $10^{\circ}C$ for 6 days, and did not produce $CO_2$ to check post fermentation. The medium of grapefruit extract fermentation by Lactobacillus plantarum CJIH 203 resulted in maximal viable counts, compared with other strains, and the extract subsequently tasted sour due to the presence of lactic acid. Lactobacillus plantarum CJIH203 was highly resistant to artificial gastric juice and intestinal juice, while Lactococcus lactis SJ09 strongly adhered to HT-29 cells. Tagatose showed the greatest ability to enhance the growth of L. plantarum SJ21, relative to the other strains. All strains were verified by safety tests such as hemolysis, gelatin hydration, and urea degradation. Therefore, these strains could be promising candidates for use in reducing excessive post-fermentation and functional products.

• The Korean Journal of Food And Nutrition
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• v.17 no.1
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• pp.8-17
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• 2004

The effect of chlorella extract on the growth and acid production of yoghurt starter was investigated in order to prepare the yoghurt added with chlorella extract. The various levels of chlorella extract powder were added to skim milk medium and the medium was fermented by single or mixed culture of 4 types of lactic acid bacteria such as Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus bulgaricus. The changes in acid production(pH, titratable acidity) and number of viable cells of the medium during fermentation in skim milk added with chlorella extract powder have determined. When chlorella extract powder was added to skim milk medium at the levels of 0.5%, 1.0%, 2.0%, and 3.0%, the addition of 0.5% chlorella extract powder with the single culture of Str. thermophilus, Lac. casei, and Lac. bulgaricus showed the highest number of viable cell counts after 9 hours incubation. And also all single cultures of the yoghurt starter produced the higher amounts of acid with the addition of 0.5% chlorella extract powder. When chlorella extract powder was added to the medium at the levels of 0.25%, 0.5%, 1.0%, and 2.0%, the addition of lower lever(0.25∼0.5%) of chlorella extract powder with the mixed culture of the lactic acid bacteria showed more the acidity of pH and the number of viable cell counts. Among the treatments tested, the addition of 0.25% chlorella extract powder with the mixed culture of Str. thermophilus and Lac. casei produced the highest number of viable cell counts after 12 hours incubation. Therefore it was suggested to manufacture the yoghurt with the addition of 0.25% chlorella extract powder and the inoculation of mixed culture of Str. thermophilus and Lac. casei for on the stimulation of growth of the yoghurt starter.

• KSBB Journal
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• v.8 no.5
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• pp.483-487
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• 1993

BSA/acids component in serum free medium (SFM) developed for the culture of hybridoma cell line, KA112, was replaced by acids/Pluronic F-68 emulsion. Protein content of SFM was minimized, and increased maximum cell density was obtained in serum-free lipids supplemented medium (SFLSM). Cell growth promotion effect of the emulsion was not affected by filtration with 0.2$\mu$m filter.

• BMB Reports
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• v.33 no.4
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• pp.332-336
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• 2000

Phenazine 1-carboxylic acid (PCA) is an antifungal antibiotic isolated from a culture filtrate of Bacillus sp. B-6 producing an acyl CoA synthetase inhibitor. This antibiotic is reported as an inhibitor of an acyl CoA synthetase from Pseudomonas sp.. Bacillus sp. B-6 was resistant to PCA up to 350 ${\mu}g/ml$. We investigated the mechanism of the resistance of Bacillus sp. B-6 to PCA. The rate of growth in a medium containing up to 100 ${\mu}g/ml$ was as rapid as the PCA-free medium. At a PCA concentration of 300 ${\mu}g/ml$, the growth rate was more than half that of the control. In this work, we purified acyl CoA synthetase from Bacillus sp. B-6 and found that this acyl CoA synthetase was much less sensitive to PCA than the acyl CoA synthetase from other source. These findings suggested that the insensitivity of Bacillus sp. B-6 acyl CoA synthetase plays an important role in the PCA resistance of this bacterium.

• Journal of Environmental Health Sciences
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• v.21 no.4
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• pp.44-48
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• 1995

26 bacterial strains capable of growing on Terephthalic acid (TPA) in minimal medium were isolated from soil and wastewater by selective enrichment culture, and among them, one isolate which was the best in the cell growth and TPA degradation was selected and identified as Pseudomonas sp. T-1 by its characteristics. Cell growth almost revealed a stationary phase at 24 hrs after cultivation. Cell growth dramatically increased in a minimal medium containing 0.1% of TPA as a sole carbon source and TPA was not detected any more at 80 hrs after cultivation. Therefore, it is suggested that Pseudomonas sp. T-1 could be effectively used for the biological treatment of wastewater containing TPA.

• Food Science and Preservation
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• v.1 no.1
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• pp.9-14
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• 1994

Soluble solids($^{\circ}$Brix), acid content and edible part ratio of Citrus unshiu collected at sorting Places in south Cheju area wee more lowered, and peel thickness was more thickened with increasing fruit size. Compared to early variety of Citurs unshiu(C. unshiu Miyakawa Mar), peel thickness of medium variety of Citurs unshiu(C. unshiu Hayashi Mar) was more thickened, and edible part ratio was more lowered with increasing fruit size. Soluble solids of medium variety of Citurs unshiu were lowered, and acid contents were increased compared to early variety. Processing properties for pressing concentrated juice was good for early variety of Citurs unshiu, especially on fruit diameter of 50-65mm. Soluble solids, acid contents and juice ratio were decreased with increasing peel thickness. The quality properties for fresh fruit with peel thickness had a good correlation on early variety of Citurs unshiu, and these data are supposed to be applied to the quality evaluation of Citurs unshiu produced in Cheju.

• Microbiology and Biotechnology Letters
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• v.23 no.1
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• pp.31-35
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• 1995

Using the alkalophillic Bacillus sp. SH-8 and its mutant Bacillus sp. SH-8M capable of growing at the neutral pH, the amino acid compositions of the cell wall and cell membrane were studied at varying cultivation pH's. The pattem of protein electrophoresis was also tested. It was elucidated that the amino acids consisting of the cell wall were alanine, glutamic acid, lysine, aspartic acid, and meso-diaminopimelic acid. There was not any significant difference in the amino acid compositqon betweeo`two straqns regardless of the culture pH. As the results of HPLC ssay, glutamic acid and aspartic aciu accounted for more than 50% in the amqno acid composytqon of the cell wall. By the isolatqon of the crude cell membrane and the SDS-PAGE analysis, it was found that there was a considerable difference qn the protein pattern when the straqns were cultured at the neutral pH. In addition, by the two dimensional gel electrophoresis, it was confirmed that there was a difference in the protein patterns between two strains cultivated at the neutral pH medium but no difference at the alkaline medium.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.5
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• pp.383-388
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• 2004

The conversion of a cellulose-producing cell ($Cel^+$) from Gluconacetobacter hansenii PJK (KCTC 10505 BP) to a non-cellulose-producing cell ($Cel^-$) was investigated by measuring the colony forming unit (CFU). This was achieved in a shaking flask with three slanted baffles, which exerted a strong shear stress. The addition of organic acid, such as glutamic acid and acetic acid, induced the conversion of microbial cells from a wild type to $Cel^-$ mutants in a flask culture. The supplementation of $1\%$ ethanol to the medium containing an organic acid depressed the con-version of the microbial cells to $Cel^-$ mutants in a conventional flask without slanted baffles. The addition of ethanol to the medium containing an organic acid; however, accelerated the conversion of microbial cells in the flask with slanted baffles. The $Cel^+$ cells from the agitated culture were not easily converted into $Cel^-$ mutants on the additions of organic acid and ethanol to a flask without Slanted baffles, but some portion of the $Cel^+$ cells were converted to $Cel^-$ mutants in a flask with slanted baffles. The conversion ratio of $Cel^+$ cells to $Cel^-$ mutants was strongly re-lated to the production of bacterial cellulose independently from the cell growth.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.11
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• pp.1608-1614
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• 2014

The objective of this study was to investigate the different dietary ratios of n-6 to n-3 (n-6/n-3) fatty acid (FA) on performance and n-6/n-3 FA in muscles of broiler chickens. A total of 300 one-day-old Cobb chicks were randomly assigned to 3 treatments of 10 replicates in each (10 birds/replicate). Birds were fed on a corn-soybean meal-based diet containing 1% oil during starter (day 1 to 21) and 2% oil during finisher (day 22 to 39) phases, respectively. Treatments of high, medium and low dietary n-6/n-3 FA were formulated by replacing rice bran oil with linseed oil to achieve n-6/n-3 FA close to >20:1, 10:1 and 5:1, respectively. Average daily gain, average daily feed intake, and feed conversion ratio were similar (p>0.05) among the treatments. Serum glucose, cholesterol and triglycerides concentrations were not affected (p>0.05) by dietary treatments. In breast, concentration of C18:3n-3 was significantly greater (p = 0.001) for medium and low vs high n-6/n-3 FA, while concentrations of C20:5n-3, C22:6n-3, total n-3 FA, and n-6/n-3 FA were significantly higher for low vs medium, and medium vs high dietary n-6/n-3 FA. In contrast, concentrations of C18:2 and mono-unsaturated FA (MUFA) were lower for low vs high dietary n-6/n-3 FA. In thigh muscles, concentrations of C20:5n-3 were higher (p<0.05) for medium and low vs high dietary n-6/n-3 FA, and concentrations of C18:3n-3, C22:6, and n-3 FA were greater (p<0.05) for medium vs high, low vs medium dietary n-6/n-3 FA. However, concentrations of C18:1, MUFA, n-6/n-3 were lower (p<0.05) for low and medium vs high dietary n-6/n-3 FA. In conclusion, lowering the dietary n-6/n-3 FA did not affect the performance of chickens, but enhanced beneficial long-chain n-3 FA and decreased n-6/n-3 FA in chicken breast and thigh, which could be advantageous for obtaining healthy chicken products.

• Journal of Animal Science and Technology
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• v.64 no.3
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• pp.481-499
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• 2022

This study aims to determine the effects of D-methionine (D-Met) isomer and the methionine precursor 2-hydroxy-4-methylthiobutanoic acid i (HMBi) supplementation on milk protein synthesis on immortalized bovine mammary epithelial cell (MAC-T). MAC-T cells were seeded using 10-cm dishes and cultured in Dulbecco's modified Eagle's medium/F12 (DMEM/F12) basic medium. The basic medium of DMEM/F12 was replaced with the lactogenic DMEM/ F12 differentiation medium when 90% of MAC-T cells reached confluency. The best dosage at 0.6 mM of D-Met and HMBi and incubation time at 72 h were used uniformly for all treatments. Each treatment was replicated six times wherein treatments were randomly assigned in a 6-well plate. Cell, medium, and total protein were determined using a bicinchoninic acid protein assay kit. Genes, proteomics and metabolomics analyses were also done to determine the mechanism of the milk protein synthesis pathway. Data were analyzed by two-way analysis of variance (ANOVA) with supplement type and plate as fixed effects. The least significant difference test was used to evaluate the differences among treatments. The HMBi treatment group had the highest beta-casein and S6 kinase beta-1 (S6K1) mRNA gene expression levels. HMBi and D-Met treatments have higher gene expressions compared to the control group. In terms of medium protein content, HMBi had a higher medium protein quantity than the control although not significantly different from the D-Met group. HMBi supplementation stimulated the production of eukaryotic translation initiation factor 3 subunit protein essential for protein translation initiation resulting in higher medium protein synthesis in the HMBi group than in the control group. The protein pathway analysis results showed that the D-Met group stimulated fructose-galactose metabolism, glycolysis pathway, phosphoinositide 3 kinase, and pyruvate metabolism. The HMBi group stimulated the pentose phosphate and glycolysis pathways. Metabolite analysis revealed that the D-Met treatment group increased seven metabolites and decreased uridine monophosphate (UMP) production. HMBi supplementation increased the production of three metabolites and decreased UMP and N-acetyl-L-glutamate production. Taken together, D-Met and HMBi supplementation are effective in stimulating milk protein synthesis in MAC-T cells by genes, proteins, and metabolites stimulation linked to milk protein synthesis.