• The Plant Pathology Journal
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• v.38 no.2
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• pp.115-130
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• 2022

Though information exists regarding the pathogenesis of the shot-hole disease (SH) in flowering cherry (FC), there has been a lack of research focusing on SH management. Therefore, here, we investigated the inhibitory activities of antagonistic bacteria against SH pathogens both in vitro and in vivo as well as their biochemical characteristics and bioactive compounds. Two biosurfactant-producing bacterial antagonists, identified as Bacillus velezensis strains JCK-1618 and JCK-1696, exhibited the best effects against the growth of both bacterial and fungal SH pathogens in vitro through their cell-free culture filtrates (CFCFs). These two strains also strongly inhibited the growth of the pathogens via the action of their antimicrobial diffusible compounds and antimicrobial volatile organic compounds (VOCs). Crude enzymes, solvent extracts, and biosurfactants of the two strains exhibited antimicrobial activities. Liquid chromatography/electrospray ionization time-of-flight mass spectrometric analysis of the partially purified active fractions revealed that the two antagonists produced three cyclic lipopeptides, including iturin A, fengycin A, and surfactin, and a polyketide, oxydifficidin. In a detached leaf assay, pre-treatment and co-treatment of FC leaves with the CFCFs led to a large reduction in the severity of the leaf spots caused by Epicoccum tobaicum and Bukholderia contaminans, respectively. In addition, the two antagonists produced indole-3-acetic acid, siderophore, and a series of hydrolytic enzymes, along with the formation of a substantial biofilm. To our knowledge, this is the first report of the antimicrobial activities of the diffusible compounds and VOCs of B. velezensis against the SH pathogens and their efficiency in the biocontrol of SH.

• Food Science and Industry
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• v.50 no.2
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• pp.37-51
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• 2017

Food packaging strategies have steadily improved with increasing demand for improved food safety, convenience, and shelf life. The development of edible film has been hailed as a technology substituting packaging using synthetic plastics. There has been a surge for research to develop antimicrobial edible films and coatings that can increase microbiological safety while preserving foods. This review addresses recent results that are useful in advancing and extending research into antimicrobial edible films. In this review, we suggest the trend of the development of antimicrobial edible film/coatings by outlining edible film materials, antimicrobial substances, antimicrobial and physical properties of the films, commercial antimicrobial edible films, and methods to statistically predict the efficacy of antimicrobial edible film/coatings, reported in recent studies.

• The Journal of Advanced Prosthodontics
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• v.9 no.3
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• pp.217-223
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• 2017

PURPOSE. This study investigated the effects of silver nanoparticle (SN) loading into hydraulic calcium silicate-based Portland cement on its mechanical, antibacterial behavior and biocompatibility as a novel dental bone substitute. MATERIALS AND METHODS. Chemically reduced colloidal SN were combined with Portland cement (PC) by the concentrations of 0 (control), 1.0, 3.0, and 5.0 wt%. The physico-mechanical properties of silver-Portland cement nanocomposites (SPNC) were investigated through X-ray diffraction (XRD), setting time, compressive strength, solubility, and silver ion elution. Antimicrobial properties of SPNC were tested by agar diffusion against Streptococcus mutans and Streptococcus sobrinus. Cytotoxic evaluation for human gingival fibroblast (HGF) was performed by MTS assay. RESULTS. XRD certified that SN was successfully impregnated in PC. SPNC at above 3.0 wt% significantly reduced both initial and final setting times compared to control PC. No statistical differences of the compressive strength values were detected after SN loadings, and solubility rates of SPNC were below 3.0%, which are acceptable by ADA guidelines. Ag ion elutions from SPNC were confirmed with dose-dependence on the concentrations of SN added. SPNC of 5.0 wt% inhibited the growth of Streptococci, whereas no antimicrobial activity was shown in control PC. SPNC revealed no cytotoxic effects to HGF following ISO 10993 (cell viability > 70%). CONCLUSION. Addition of SN promoted the antibacterial activity and favored the bio-mechanical properties of PC; thus, SPNC could be a candidate for the futuristic dental biomaterial. For clinical warrant, further studies including the inhibitory mechanism, in vivo and long-term researches are still required.

• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.376-382
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• 1999

A methicillin-resistant Staphylococcus aureus (MRSA) isolate was recovered from a 9-month-old female Shih-Tzu dog with canine distemper virus infection. We performed in vitro antimicrobial susceptibility test to determine the most effective antimicrobial drug against the isolate and thus, to emphasize its potential clinical importance in animal practices. Isolate was confirmed MRSA by oxacillin agar screening test. The isolate was fully resistant to all $\beta$-lactam antibiotics and was susceptible to glycopeptides. Of the other antibiotics, mupirocin, TMP/SMZ (trimethoprim-sulfamethoxazole), and chloramphenicol showed inhibitory effect at the concentration of 4x MIC. The MICs ranged 0.25->$128{\mu}g/ml$, and MBCs ranged 0.5->$128{\mu}g/ml$. The combined TMP/SMZ with cefamandole or novobiocin showed synergistic effect, whereas the combination of novobiocin plus cefamandole or teicoplanin resulted in antagonistic effects. Although MRSA in animals so far has been reported in the geographically limited countries, at least theoretically, it could be occurred in the future more frequently through either human or animal origin. The use of this combination may be of value in this situation. As with all antimicrobial agents, inappropriate or unnecessarily prolonged therapy may contribute to the emergence of resistance strains and loss of efficacy.

• Textile Coloration and Finishing
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• v.24 no.4
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• pp.247-252
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• 2012

The objective of this study was to find an appropriate method and process for protecting the green color in bamboo leaves and subsequent extraction of the green colorants, chlorophyll. Various inorganic salts including cupric sulfate, ferric sulfate, and zinc chloride were employed as green color protectors. Accordingly, the effects of metal salts and treatment conditions on color protection were investigated to find appropriate protector and conditions. And also, the efficacy of bamboo colorants as a natural green dye was evaluated through dyeing and colorfastness tests. Antimicrobial activity of dyed fabrics was measured by shake flask method in terms of bacterial reduction rate using Staphylococcus aureus(ATCC 6538). On the basis of experimental results for stabilizing bamboo leaves colorants, it was confirmed that Cu was the most appropriate metal type considering dye uptake, photostability and light fastness, and its optimum concentration was 0.025%. After the stabilization, the colorants were extracted efficiently at NaOH aqueous solution of 1.00%. It was concluded that bamboo leave has a high potentiality as new resources to produce a natural green dye with antimicrobial functionality.

• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.297-300
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• 2003

In order to select probiotics with a high survival rate in gut and the growth inhibition of virulent pathogens to human beings or animals, we have screened lactic acid bacteria and yeasts from Jeot-gal to assess resistance against the artificial gastric acid and bile juice. Lactic acid bacteria and yeasts isolated were incubated for 24 h in artificial bile juice after incubation for 2 h in artificial gastric acid. Especially, strain HW 161 and strain NK 181 showed the higher survival for 2 h incubation in artificial gastric acid. All of 3 strains of lactic acid bacteria and 2 strains of yeast were showed higher growth rate than the control in artificial bile. The antimicrobial activity of lactic acid bacteria and yeasts was also investigated to prove efficacy as probiotic organisms. Lactic acid bacteria were shown the inhibition of Gram positive and negative bacteria, but yeasts narrow inhibition.

• Korean Journal of Pharmacognosy
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• v.21 no.3
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• pp.217-222
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• 1990

Ulmi Cortex has been used for edema, articular rhematism and acne, etc in oriental medicine. Here, experimentally the MeOH extract showed significant anti-inflammatory action, inhibitory effect of leukocyte emigration in rats and the growth inhibition of Sta. aureus, Strep. faecalis, Psu. aeruginosa and Bacillus sp. The ether layer showed analgesic effect stronger than that of MeOH extract and BuOH layer showed antimicrobial activity stronger than that of the other layer.

• Korean Journal Plant Pathology
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• v.12 no.1
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• pp.80-84
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• 1996

토양에서 분리한 방선균류(actinomycetes) GT103 균주의 배양여액 및 균체추출물은 담배의 주요 병원균인 담배 줄기속마름병균(Erwinia carotovora subsp. carotovora), 담배 탄저병균(Colletotrichum tabacum), 담배역병균(Phytophthora nicotianae var. nicotianae)등에 강한 항균활성을 보였다. 항균활성물질은 용매 추출, silica gel chromatography, HPLC 등을 실시하여 분리.정제하였으며 UV, IR, FAB-MS, \ulcornerH-NMR, \ulcornerC-NMR 분석결과 actinomycin group의 펩타이드계 항생 물질인 actinomycin C\ulcorner로 동정되었다. 이 활성물질의 담배 탄저병에 대한 방제효과는 50$\mu\textrm{g}$/ml 농도에서 100%, 10$\mu\textrm{g}$/ml 농도에서 90%의 방제효과를 보였다.

• Proceedings of the SCSK Conference
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• 1992.09a
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• pp.46-68
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• 1992

To investigate the effect on the antimicrobial activity against S.aureus ATCC 6538, E.coli KCTC 1039 and cell toxic level against transformed mouse fibroblast L929 in formula added with various concentrations of UVB blockers commonly used in cosmetic products, these experiments were carried out by preservative efficacy testing methods and in vitro cytotoxicity methods. The results obtained were as follow ; 1) Octyl Dimethyl PABA had a broad antibacterial spectrum against the Gram (+) and the Gram(-) bacteria at 5.84 % concentration, but not Octyl Methoxycinnamate. 2) Antibacterial activity was decreased in a combined UVB blocker system of squalane base. Especially, Octyl Dimethyl PABA was inactivated by Octyl Methoxycinnamate at 5.84% concentration to a large extents , but not 4-Methylbenzylidene Camphor. 3) Within in vitro cytotoxicity by use of mouse fibroblast L929 on UV-B blockers, NR assay was more excellent than MTT assay on quantitative

• Mycobiology
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• v.47 no.1
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• pp.105-111
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• 2019

Many of the fungicides and antibiotics currently available against plant pathogens are of limited use due to the emergence of resistant strains. In this study, we examined the effects of diphenyleneiodonium chloride (DPIC), an inhibitor of the superoxide producing enzyme NADPH oxidase, against fungal and bacterial plant pathogens. We found that DPIC inhibits fungal spore germination and bacterial cell proliferation. In addition, we demonstrated the potent antibacterial activity of DPIC using rice heads infected with the bacterial pathogen Burkholderia glumae which causes bacterial panicle blight (BPB). We found that treatment with DPIC reduced BPB when applied during the initial flowering stage of the rice heads. These results suggest that DPIC could serve as a new and useful antimicrobial agent in agriculture.