• Food Science of Animal Resources
• /
• v.36 no.2
• /
• pp.186-193
• /
• 2016

This study aimed to inhibit Escherichia coli (E. coli) O157:H7 artificially contaminated in fresh meat using bacteriophage. Among 14 bacteriophages, the highly lytic bacteriophage BPECO19 strain was selected to inhibit E. coli O157:H7 in artificially contaminated meat samples. Bacteriophage BPECO19 significantly reduced E. coli O157:H7 bacterial load in vitro in a multiplicity of infection (MOI)-dependent manner. E. coli O157:H7 was completely inhibited only in 10 min in vitro by the treatment of 10,000 MOI BPECO19. The treatment of BPECO19 at 100,000 MOI completely reduced 5 Log CFU/cm² E. coli O157:H7 bacterial load in beef and pork at 4 and 8h, respectively. In chicken meat, a 4.65 log reduction of E. coli O157:H7 was observed at 4 h by 100,000 MOI. The treatment of single bacteriophage BPECO19 was an effective method to control E. coli O157:H7 in meat samples.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.2
• /
• pp.184-188
• /
• 2013

In the continued search for inhibitors of enoyl-acyl carrier protein (ACP) reductase, we found that four acylbenzenediol sulfate metabolites from Streptomyces sp. AN1761 potently inhibited bacterial enoyl-ACP reductases of Staphylococcus aureus, Streptococcus pneumoniae, and Mycobacterium tuberculosis. Their structures were identified as panosialins A, B, wA, and wB by MS and NMR data. They showed stronger inhibition against S. aureus FabI and S. pneumoniae FabK with $IC_{50}$ of 3-5 ${\mu}M$ than M. tuberculosis InhA with $IC_{50}$ of 9-12 ${\mu}M$. They also exhibited a stronger antibacterial spectrum on S. aureus and S. pneumoniae than M. tuberculosis. In addition, the higher inhibitory activity of panosialin wB than panosialin B on fatty acid biosynthesis was consistent with that on bacterial growth, suggesting that they could exert their antibacterial activity by inhibiting fatty acid synthesis.

• Journal of fish pathology
• /
• v.37 no.1
• /
• pp.37-48
• /
• 2024

This study evaluated in vitro antimicrobial properties of Bacillus subtilis KCTC 1326 as an environmentally friendly alternative to antibiotics. B. subtilis KCTC 1326 was characterized on biochemical properties and antibiotics susceptibility. It exhibited antimicrobial effects against all 12 species of fish bacteria used in this experiment. Among them, the largest antibacterial zone was observed for Streptococcus parauberis (34 mm), while the smallest antibacterial zone was observed for Citrobacter freundii (8 mm). Additionally, in the co-culture inhibitory assay of B. subtilis and Edwardsiella piscicida, the growth of E. piscicida was suppressed with increasing concentrations of B. subtilis KCTC 1326, with complete inhibition observed at 107 and 108 CFU/mL of B. subtilis KCTC 1326 after 24 hours of incubation. Moreover, at 48 hours of incubation, the growth of E. piscicida was inhibited across all concentration ranges of B. subtilis KCTC 1326. Therefore, this study indicated the utilizing of B. subtilis KCTC 1326 as an antimicrobial for controlling fish bacterial diseases.

• Korean Journal of Organic Agriculture
• /
• v.24 no.4
• /
• pp.945-955
• /
• 2016

To date, chemical managements of plant bacterial diseases are complicated by limitations on use of antibiotics in agriculture, antibiotic resistance development, and limited efficacy of alternative control agents. In this study, thus, we performed screening of eco-friendly farming material (notice no. 2-4-064) containing tannic acid as new antibacterial-activity against 7 plant bacterial pathogens: Pectobacterium carotovorum subsp. carotovorum (Pcc), Ralstonia solanacearum (Rs), Acidovorax avenae subsp. citrulli (Aac), Xanthomonas cirti pv. citri (Xcc), Erwinia pyrifoliae (Ep), Clavibacter michiganensis subsp. michiganensis (Cmm), and Streptomyces scabies (Sc), Initial screening of antibacterial effects of eco-friendly farming material was performed using the paper disk diffusion method and co-cultivation in broth culture. Tannic acid based eco-friendly farming material showed inhibitory effect against Pcc, Rs, Aac, Xcc, Cmm, and Ss, whereas it did not show inhibition zone against Ep. However, when it tested by co-cultivation in broth culture, it showed strong inhibition effect against all pathogens that declined growth curve compared to bacterial pathogen only. Interestingly, when we observed morphological changes on those pathogens by SEM, cell morphologies of 7 pathogens were slightly changed that seem to be malfunction in their cell envelope.

• Fisheries and Aquatic Sciences
• /
• v.22 no.12
• /
• pp.30.1-30.11
• /
• 2019

Marine natural products isolated from the sponge Fascaplysinopsis cf reticulata, in French Polynesia, were investigated as an alternative to antibiotics to control pathogens in aquaculture. The overuse of antibiotics in aquaculture is largely considered to be an environmental pollution, because it supports the transfer of antibiotic resistance genes within the aquatic environment. One environmentally friendly alternative to antibiotics is the use of quorum sensing inhibitors (QSIs). Quorum sensing (QS) is a regulatory mechanism in bacteria which control virulence factors through the secretion of autoinducers (AIs), such as acyl-homoserine lactone (AHL) in gram-negative bacteria. Vibrio harveyi QS is controlled through three parallel pathways: HAI-1, AI-2, and CAI-1. Bioassay-guided purification of F. cf reticulata extract was conducted on two bacterial species, i.e., Tenacibaculum maritimum and V. harveyi for antibiotic and QS inhibition bioactivities. Toxicity bioassay of fractions was also evaluated on the freshwater fish Poecilia reticulata and the marine fish Acanthurus triostegus. Cyclohexanic and dichloromethane fractions of F. cf reticulata exhibited QS inhibition on V. harveyi and antibiotic bioactivities on V. harveyi and T. maritimum, respectively. Palauolide (1) and fascaplysin (2) were purified as major molecules from the cyclohexanic and dichloromethane fractions, respectively. Palauolide inhibited QS of V. harveyi through HAI-1 QS pathway at 50 ㎍ ml^-1 (26 μM), while fascaplysin affected the bacterial growth of V. harveyi (50 ㎍ ml^-1) and T. maritimum (0.25 ㎍). The toxicity of fascaplysin-enriched fraction (FEF) was evaluated and exhibited a toxic effect against fish at 50 ㎍ ml^-1. This study demonstrated for the first time the QSI potential of palauolide (1). Future research may assess the toxicity of both the cyclohexanic fraction of the sponge and palauolide (1) on fish, to confirm their potential as alternative to antibiotics in fish farming.

• Horticultural Science & Technology
• /
• v.32 no.6
• /
• pp.879-886
• /
• 2014

This study was conducted to test in vitro the antagonistic effect of composted liquid manure (CLM) against soil-borne turfgrass pathogenic fungi, Rhizoctonia solani AG-2-2 (IIIB) (brown patch), R. solani AG-2-2 (IV) (large patch), and Sclerotinia homoeocarpa (dollar spot) for environmentally friendly turfgrass management. CLMs were collected from 9 livestock excretion treatment facilities around the country including Gunwi (GW), Hapcheon (HC), Hoengseong (HS), Icheon (IC), Iksan (IS), Muan (MA), Nonsan (NS), and Yeoju (YJ). CLMs of IC, GW, and IS showed s ignificant (p < 0.05) mycelium growth inhibition that was 17.8%, 20.4%, and 48.0% against R. solani AG-2-2 (IIIB), R. solani AG-2-2 (IV), and S. homoeocarpa, respectively. A t otal of 110 bacterial isolates were obtained from the CLMs that showed antagonistic effects. Among them, 5, 4, and 10 microbe isolates showed promising antifungal activity against mycelium growth of R. solani AG-2-2 (IIIB), R. solani AG-2-2 (IV), and S. homoeocarpa, respectively. The bacterial isolates ICIIIB60, GWIV70, and ISSH20 effectively inhibited the mycelial growth of three soil-borne turfgrass pathogens. Selected bacterial isolates were identified as Alcaligenes sp., Bacillus licheniformis Ab2, and B. subtilis C7-3 through 16s rDNA gene sequence analysis. Among 5 fungicides, the most compatible fungicide with ICIIIB60, GWIV70, and ISSH20 was tebuconazol, toclofos-methyl and toclofos-methyl, respectively. These findings suggested that CLMs could be effectively used not only as organic liquid fertilizer sources but also as biological control agents for soil-borne turfgrass diseases such as brown patch, large patch, and dollar spot.

• Journal of Animal Science and Technology
• /
• v.46 no.6
• /
• pp.1023-1030
• /
• 2004

This study was carried out to investigate the effect of chitosan on shelf-life and quality of vaccum-packaged seasoned pork. Chitosan was used 120 kDa and various concentration such as 0.05 - 1.0%. The total bacterial counts, pH, oxidation of lipid, surface color and water holding capacity of the sample were determined during storage periods. The total bacterial counts of seasoned pork without chitosan were increased the latter period of storage, but that of seasoned pork with chitosan was decreased such as inhibition of bacterial growth effectively. Effect on shelf-life of seasoned porks when added 0.100/0, 0.50% and 1.00% of chitosan, respectively were maintained pretty well during 10 days of storage. Content of TBARS in seasoned pork without chitosan was increased than that of seasoned pork with chitosan during period of storage. And also effect of self-life and inhibition of lipid oxidation were increased with following concentration of chitosan. The variation of pH was low and stable in seasoned pork with chitosan during periods of storage. The change of color such as lightness(L^*), redness(a^*), yellowness(b^*) in seasoned pork with chitosan was detected higher than that seasoned pork without chitosan. Water holding capacity of seasoned pork with low in the early period of storage. These colors and water holding capacity were very stable untill 10 days of storage.

• Korean Chemical Engineering Research
• /
• v.48 no.6
• /
• pp.690-694
• /
• 2010

In this study, herbal wood vinegar including Bambusoideae, Cinnamomi Cortex, Zingiberis Rhizoma was tested to see possibility for cosmetic or skin related medicine. Anti-oxidation effect of herbal wood vinegar was tested by DPPH free radical scavenging activity, and showed 97% inhibition rate at $50{\mu}g/ml$. Anti-bacterial effect was tested by disc diffusion method, and it indicated strong anti-bacterial activity against normal skin flora Staphylococcus aureus. Whitening effect was measured by tyrosinase inhibition assay, and it was lower compared with vitamin C. Stability test was done by MTT assay, and cell toxicity was relatively high. Stability was also checked, and there was not significant change in color, aroma, appearance and pH during storage. Anti-atopic dermatitis test was done by hairless mouse and herbal wood vinegar recovered damaged skin to almost normal condition after 9 days of application. IgE concentration in herbal wood vinegar treated mouse was also reduced 30% compared with control. From the study, herbal wood vinegar showed good anti-oxidation, anti-bacterial and anti-atopic dermatitis effect, and had promising application in cosmetic or skin related medicine.

• Food Science and Biotechnology
• /
• v.15 no.5
• /
• pp.817-819
• /
• 2006

8-Quinolinol and other quinolinol derivatives were evaluated with regard to their growth-inhibitory effects against intestinal bacteria, using the paper disk-agar diffusion method. The observed growth responses varied according to the chemicals and dosages used, as well as the bacterial species tested. 8-Quinolinol showed a significant inhibitory effect against Clostridium difficile, C. perfringens, and Escherichia coli, at 5, 2, 1, and 0.5 mg/disk, and also exhibited a very strong inhibitory effect at 0.25 mg/disk. At low concentrations, 8-quinolinol had strong inhibitory effects against C. perfringens at 0.1 and 0.05 mg/disk; 8-quinolinol also manifested a moderate inhibitory effect against C. perfringens at 0.025 mg/disk. Furthermore, 8-quinolinol revealed moderate and weak growth inhibition against C. difficile and E. coli at concentrations of 0.1 and 0.05 mg/disk, respectively, but 2-quinolinol, 4-quinolinol, and 6-quinolinol evidenced no growth inhibition against B. bifidum, B. longum, C. difficile, C. perfringens, E. coli, or L. casei. The inhibitory effects of 8-quinolinol against C. difficile, C. perfringens, and E. coli lead to its consideration as a possible therapeutic modality for the treatment of diseases associated with harmful intestinal bacteria.

• Mycobiology
• /
• v.36 no.2
• /
• pp.93-98
• /
• 2008

Two Schiff base ligands $L_1\;and\;L_2$ were obtained by the condensation of glycylglycine respectively with imidazole-2-carboxaldehyde and indole-3-carboxaldehyde and their complexes with Zn(II) were prepared and characterized by microanalytical, conductivity measurement, IR, UV-Vis., XRD and SEM. The molar conductance measurement indicates that the Zn(II) complexes are 1:1 electrolytes. The IR data demonstrate the tetradentate binding of $L_1$ and tridentate binding of $L_2$. The XRD data show that Zn(II) complexes with $L_1\;and\;L_2$ have the crystallite sizes of 53 and 61 nm respectively. The surface morphology of the complexes was studied using SEM. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola and Candida albicans by the disc diffusion method. A comparative study of inhibition values of the Schiff base ligands and their complexes indicates that the complexes exhibit higher antimicrobial activity than the free ligands. Zinc ions are proven to be essential for the growth-inhibitor effect. The extent of inhibition appeared to be strongly dependent on the initial cell density and on the growth medium.