• Food Science of Animal Resources
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• v.38 no.4
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• pp.727-736
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• 2018

In this study, an immuno-magnetic bead (IMB)-based assay was developed to simultaneously detect Escherichia coli, Staphylococcus aureus, and Salmonella spp. and was tested in four animal-derived foods: beef, ham, egg, and ricotta cheese. The IMB-based assay exhibited good specificity by binding to five E. coli serotypes [capture efficiency (CE) average (avg.) 90.4%], five S. aureus strains (CE avg. 91.4%), and five Salmonella serotypes (CE avg. 95.4%) but not binding to non-target bacteria (CE<10%). Furthermore, the assay detected all three pathogens with a detection limit of 10 CFU/g without the need for enrichment or additional platforms. Since the results demonstrated that the IMB-based assay can effectively separate and enrich target bacteria from a variety of animal-derived food matrixes, the assay exhibits good specificity for potential use in providing rapid, immunological, presumptive identification of pathogenic bacteria.

• Korean Journal of Veterinary Research
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• v.48 no.2
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• pp.145-151
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• 2008

This study was conducted to investigate biochemical properties and O group serotypes of pathogenic 203 Escherichia (E.) coli isolates from poultry with collibacillosis in Korea during the period from April 2003 to December 2005. Biochemical and fermentative properties of 203 isolates of E. coli tested were in accordance with Cowan and Steel's classification standard. One hundred and forty one isolates (69.5%) could be classified into a total of 20 O serotypes. Among them, the predominant O groups were O78 (32.5%), O88 (7.8%), O15 (6.8%), O141 (6.4%), and O158 (3.0%) in decreased order. Other infrequently encountered serogroups included : O8 (2%), O161 (2%), O20 (1.5%), O125 (1.5%), O2 (1%). And O6, O18, O24, O46, O76, O109, O119, O138, O139 and O148 had a frequency of 0.5%, respectively. Sixty two isolates (30.5%) were non-typeable with standard 173 O antisera used in this study.

• Journal of Microbiology and Biotechnology
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• v.19 no.6
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• pp.604-609
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• 2009

To investigate the potential use of microbial heme as an iron source, recombinant Escherichia coli coexpressing ALA synthase (HemA) as well as the NADP-dependent malic enzyme (MaeB) and dicarboxylic acid transporter (DctA) were cultured. The typical red pigment extracted from the recombinant E. coli after 38 h showed highest absorbance at 407 nm, and the amount of iron in 38.4 mg of microbial heme extract derived from 6-1 fermentation broth was 4.1 mg. To determine the commercial potential of the recombinant E.coli-synthesized iron-associated heme as an iron source, mice were fed the iron-free provender with the microbial heme extract. The average body weight reduction of mice fed non-iron provender was 2.3%, whereas no detectable weight loss was evident in mice fed microbial heme addition after 15 days. The heme content of the blood from microbial heme fed mice was 4.2 mg/ml whereas that of controls was 2.4 mg/ml, which implies that the microbial heme could be available for use as an animal iron source.

• Journal of fish pathology
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• v.24 no.3
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• pp.297-305
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• 2011

A trap identification system for isolating functional sequences to allow the constitutive expression of foreign protein from Edwardsiella tarda was developed. Using the green fluorescent protein (GFP) reporter-based trap system, various functional sequences to drive heterologous expression of the GFP were selectable in Escherichia coli host. However from the bioinformatic sequence analysis, all the segments predicted as regulatory regions were not native promoters actually existing upstream of endogenous E. tarda genes. Instead, a number of non-authentic sequences, possibly resulted from the random shuffling and/or intermolecular ligation were also proven to be able to display a potent GFP expression in the recombinant E. coli. Further analysis with selected clones showed that both authentic and non-authentic sequences could function in as a constitutive promoter, leading quite a consistent and stable GFP expression after repetitive subcultures. Microscopic examination also confirmed the uniform pattern of GFP expression in every host bacterium. Semi-quantitative assay of GFP showed that there was no clear relationship between expression levels and organizational features of the promoters trapped. Functional promoter-like elements achieved in the present study could be a good starting material for multivalent genetic engineering of E. tarda in order to produce recombinant vaccines in a cost-effective fashion.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.257-264
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• 2005

This experiment was carried out to investigate the effect of red ginseng extract on the growth of Lactobacillus sp. (L acidophilus, L casei, L salivarius), Escherichia coli and Listeria monocytogenes in pH controled medium by $\beta-Glycerol\;PO_4$ buffer. The growth of Lactobacillus sp. was show a similar pattern in control and MRS broth with red ginseng extract $1.0\%$ but was remarkably show inhibiting in MRS broth with over $2.0\%$ red ginseng extracts. The growth of E coli was inhibited in Trypticase soy broth with $1.0\%$ red ginseng extracts. Also the growth of L monocytogenes was inhibited in Trypticase soy broth with $5.0\%$ red ginseng extract The growth of L acidophilus KCTC3150, L casei KCTC3189, L salivarius ssp. salivarius CNU27, and E coli KCTC1039, L monocytogenes KCTC3443 were remarkably inhibited in pH non-control medium and pH control medium with $10\%$ red ginseng extract These results was suggested to effect of inhibition of microorganisms growth not pH decrease by organic acid but another components in red ginseng extract.

• Journal of Microbiology and Biotechnology
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• v.29 no.6
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• pp.944-951
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• 2019

Lipases are industrial enzymes that catalyze both triglyceride hydrolysis and ester synthesis. The overexpression of lipase genes is considered one of the best approaches to increase the enzymatic production for industrial applications. Subfamily I.2. lipases require a chaperone or foldase in order to become a fully-activated enzyme. The goal of this research was to isolate, clone, and co-express genes that encode lipase and foldase from Burkholderia territorii GP3, a lipolytic bacterial isolate obtained from Mount Papandayan soil via growth on Soil Extract Rhodamine Agar. Genes that encode for lipase (lipBT) and foldase (lifBT) were successfully cloned from this isolate and co-expressed in the E. coli BL21 background. The highest expression was shown in E. coli BL21 (DE3) pLysS, using pET15b expression vector. LipBT was particulary unique as it showed highest activity with optimum temperature of $80^{\circ}C$ at pH 11.0. The optimum substrate for enzyme activity was $C_{10}$, which is highly stable in methanol solvent. The enzyme was strongly activated by $Ca^{2+}$, $Mg^{2+}$, and strongly inhibited by $Fe^{2+}$ and $Zn^{2+}$. In addition, the enzyme was stable and compatible in non-ionic surfactant, and was strongly incompatible in ionic surfactant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.1
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• pp.123-127
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• 2011

This study was conducted to decrease the microbial hazard in kimchi saline water with microwave plasma sterilization system and to evaluate the inactivation of foodborne pathogens by the microwave plasma sterilization system as a non-thermal treatment. Contamination of coliform, Escherichia coli, and yeasts and molds were detected in the used saline water, and the microbial populations increased as the saline water was reused repeatedly. The $D_{10}$-values of E. coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes by the microwave plasma sterilization system were 0.48, 0.52, and 0.45 cycle, respectively. In addition, the microbial populations of coliform, E. coli, Salmonella spp., total aerobic bacteria, and yeasts and molds in the used kimchi saline water were significantly decreased by treating the saline water using the microwave plasma sterilization system. Therefore, these results suggest that microwave plasma sterilization system can be useful in improving the microbial safety of the used saline water.

• Journal of Microbiology and Biotechnology
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• v.5 no.4
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• pp.188-193
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• 1995

A Brevibacterium flavum gene coding for glucose permease of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) was cloned by complementing the Escherichia coli ZSCl13 mutations affecting a ptsG gene with the B. flavum genomic library. From the E. coli clone grown as red colony on a MacConkey plate supplemented with glucose as an additional carbon source, a recombinant plasmid was isolated and named pBFT93. The plasmid pBFT93 was identified as carrying a 3.6-kb fragment of B. flavum chromosomal DNA which enables the E. coli transformant to use glucose or man nose as a sole carbon source in an M9 minimal medium. The non-metabolizable sugar analogues, 2-deoxy-D-glucose (2-DG) and methyl-$\alpha$-D-glucopyranoside (MeGlc) affected the growth of ZSCl13 cells carrying the plasmid pBFT93 on minimal medium supplemented with non-PTS carbohydrate, glycerol, as a sole cabon source, while the analogues did not repress the growth of ZSCl13 cells without pBFT93. It was also found that both $2-deoxy-D-[U-^{14}C]glucose{\;}and{\;}methyl-{\alpha}-D-[U-^{14}C]glucopyranoside$ could be effectively transported into ZSCl13 cells transformed with plasmid pBFT93. Several in vivo complementation studies suggested that the B. flavum DNA in pBFT93 encodes a glucose permease specific for glucose and mannose.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.4
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• pp.394-400
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• 1992

In the isolated 280 Actinomycetes strains, 12 groups of Streptomyces were 87.2% and 3groups of Non-Streptomyces were 12.8%, respectively. Streptomyces with sporophore of the spiral chain form reached to 80% of all the Streptomyces isolates. Surface morphology of spores have been determined with the electron microscope ; two groups have a spiny surface, 10 groups have a smooth surface. Isolated Actinomyceles groups were indentified as Streptomycetes groups and Non-Streptomyces groups. Actinomycetes isolates were selected as the strains having predominant antibacterial activities against the microorganisms among the 15 groups which has antibacterial activities. Selected Actinomycetes isolates showed high antibiotic sensitivity of S-9 strain(8.46 r/ml), S-6 strain(6.23 r/ml), S-2 strain(7.24 r/ml) against Pseudomonas aeruginosa (ATCC 27857), Escherichia coli (ATCC 25922) and Staphylococcus aureus(ATCC 6538).

• Journal of fish pathology
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• v.24 no.3
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• pp.279-287
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• 2011

Transcriptional response patterns of mud loach (Misgurnus mizolepis; Cypriniformes) hepcidin, a potential ortholog to human hamp1, in response to experimental challenges with non-pathogenic and pathogenic bacterial species were analyzed based on the semi-quantitative reverse transcription-PCR assay. Mud loach hepcidin transcripts were much more preferentially induced by pathogenic bacterial species (Edwardsiella tarda and Vibrio anguillarum) causing apparent pathological symptoms than by non-pathogenic species (Escherichia coli and Bacillus thuringiensis) displaying neither clinical signs nor mortality. However in overall, the induced amounts of hepcidin transcripts were positively related with the number of bacterial cells delivered in both pathogenic and non-pathogenic bacterial species. Inducibility of hepcidin transcripts were variable among three tissues examined (liver, kidney and spleen) in which kidney and spleen were more responsive to the bacterial challenge than liver. Time course expression patterns of hepcidin mRNAs after challenge were different between groups challenged with pathogenic and non-pathogenic species, although the overall pattern of hepcidin expression was in accordance with that generally observed in battery genes appeared during early phase of inflammation. Fish challenged with E. coli (non-pathogenic) showed the significant induction of hepcidin transcripts within 24 hr post injection (hpi) but the level was rapidly declined to the basal level either at 48 or 96 hpi. On the other hand, hepcidin transcript levels in E. tarda (pathogenic)-challenged fish were continuously elevated until 48 hpi, then downregulated at 96 hpi, although the level at 96 hpi was still significantly higher than control level observed in non-challenged fish. This expression pattern was consistent in all the three tissues examined. Taken together, our data indicate that hepcidin is tightly in relation with pathological and/or inflammation status during bacterial challenge, consequently providing useful basis to extend knowledge on the host defensive roles of hepcidin under infectious conditions in bony fish.