• Journal of Plant Biotechnology
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• 제47권1호
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• pp.100-106
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• 2020

Coix lacryma-jobi (Hanjeli) is known to posses anti-microbial properties. Therefore, phytochemical compounds of C. lacryma-jobi have been studied to produce novel antimicrobial agents as treatments against antibiotic-resistant bacteria.The objective of this study was to determine the phytochemical composition and antibacterial activity of the C. lacryma-jobi oil against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The phytochemical composition of the oil was determined via gas chromatography mass spectrophotometry (GC-MS). Moreover, agar disk and agar well diffusion were employed to screen the antibacterial activity of the oil. An agar well diffusion test was implemented to determinate MIC's (minimum inhibitory concentrations). Dodecanoic acid, tetradecanoic acid, 2,3-dihydroxypropylester, 1,3-dioctanoin, N-methoxy-N-methyl-3,4-dihydro-2H-thiopyran6-carboxamide, propanamide, 5-Amino-1-(quinolin-8-yl)-1,2,3-triazole-4-carboxamide, and pyridine were identified in the C. lacryma-jobi oil. The MIC value of the oil was 0.031 g/L and the MBC of the oil was 0.125 g/L effective in all test bacteria. Dodecanoic acid displayed inhibitory activity against gram-positive and gram-negative bacteria. Therefore, our research demonstrated C. lacryma-jobi (Hanjeli) oil exhibited antibacterial activity against E. coli, S. aureus, and B. subtilis. These research suggest that C. lacryma-jobi root oil could be used for medicinal purposes; however clinical and in vivo tests must be performed to evaluate its potential as an antibacterial agent.

• Mycobiology
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• 제31권2호
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• pp.81-85
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• 2003

Antifungal properties of methyl 2-benzimidazole carbamate(BMC) were investigated using 16 fungi. Cytotoxicity test of BMC revealed that the morphology of HeLa cells was considerably deformed even at the concentrations as low as 0.1 ppm. Minimum inhibitory concentration(MIC) values of BMC for 7 fungi among the 16 tested ones were lower than $1.95{\times}10^{-4}{\mu}g/ml$, while Aspergillus flavus showed an MIC value higher than 1.0 ${\mu}g/ml$. Tolerance induction against BMC was successful only for Paecilomyces farinosus LAR10, contrary to the expectation that tolerance would be induced for the fungi having high MIC values such as Aspergillus niger ATCC 9642 and A. flavus ATCC 9643. Spore germination of A. niger ATCC 9642 was suppressed by BMC. However the mycelial growth of the fungus once germinated was not retarded at all by BMC up to 8 MIC. Addition of lanosterol provided a remedy for the reduced germination rate of A. niger ATCC 9642 spores.

• 동의생리병리학회지
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• 제16권6호
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• pp.1184-1189
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• 2002

Allii sativi Bulbus(garlic) have been shown to possess medicinal value, in particular, antimicrobial activity. In this study, we compared the efficacy on some pathogenic bacteria and fungus among several different extracts(water, hexane, ethyl acetate, methanol, chloroform) of Allii sativi Bulbus. Animal pathogenic bacteria and fungus(S. gallinarium: KCTC 2441, S. flexneri: KCTC 2361, E. cloacae: KCTC 2006, K. pneumonia: KCTC 2208, C. albicans: KCTC 1940) were used to test by measurement of minimum inhibitory concentrations(MIC) and disc diffusion. Allii sativi Bulbus were cut and mixed with water at 37℃ about 24 h and filtered, and several different solvents(hexane, chloroform, ethyl acetate, methanol) were respectively added to separate the fraction of each solvent. The antimicrobial(bacteriocidal) and antifungal effect were apparently shown from water extract, hexane and ethyl acetate extract against using strains(Staphylococcus gallinarium, Shigella flexneri, Enterobacter doacae, Klebsiella pneumonia, Candida albicans). Especially, the water extract showed the superior efficacy. And the clear zone size of water extract (11～27 mm) was greater than that of gentamycin, hexane extract and ethyl acetate extract against S. gallinarium. S. flexneri, K. pneumonia and C. albicans. Minimum inhibitory concentrations(MIC) of water extract appeared to around 2.0～7.5 ㎎/㎖ against S. gallinarium, S. flexneri, E. cloacae and K. pneumonia. The greater activity was shown by water extract because the MIC of water extract for C. albicans observed in very low concentration(<1.0 ㎎/㎖) compared to hexane(5.0 ㎎/㎖) and ethyl acetate(10.0 ㎎/㎖). Therefore, these results exhibited that water extract of Allii sativi Bulbus have stronger antimicrobial activity than hexane and ethyl acetate extract, and may be useful as topical medicine of superficial infections causing C. albicans as well as antifungal agents.

• 한국어병학회지
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• 제20권3호
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• pp.249-255
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• 2007

본 연구에서는 우리나라와 일본의 담수어에서 분리된 운동성 aeromonads 7균주와 American Type Culture Collection (ATCC)에서 분양받은Aeromonas hydrophila 4균주의 표현형적 특성을 API20E와 APIZYM 방법으로 평가하고, 7종류의 항생제에 대한 최소 성장 억제 농도 (minimum inhibitory concentrations; MICs) 를 측정하였다. API20E 시험 결과 시험한 모든 균주는 (n=7) 운동성 aeromonads로 동정되었다. API20E시험에서lysine decarboxylase와mannitol, rhamnose, amygdalin, arabinose를 포함한 4종류의 carbohydrates의 산 생성은 균주에 따라 다른 반응을 나타내었다. APIZYM 시험을 이용한 효소 활성능을 평가한 결과, 모든 시험된 균주가valine arylamidase, cystine arylamidase, α-chymotrypsin, α-galactosidase, β-glucuronidase, α-glucosidase, α-mannosidase, α-fucosidase반응에서 음성 반응을 나타내었으나, 비록 그 효소 활성의 강도에서 차이는 있었으나alkaline phosphatase, esterase-lipase, leucine arylamidase, β-galactosidase, N-acetyl-β-glucosaminidase 모든 균주에서 양성 반응이 나타났다. 최소 성장 억제농도를 시험한 결과, 시험된 모든 균주는 ampicillin sodium (MIC>100㎍/ml) 에 내성을 가지며 chloramphenicol (MIC≤1.6㎍/ml) 감수성을 나타내었다. 그러나 1998년 이후에 분리된 3균주 (AC9804, AC0202, GMA0361)는 tetracycline (MIC=50㎍/ml) 모두 저항성이 있었으며, AC9804는 oxolinic acid (MIC=12.5㎍/ml), GMA0361는 kanamycin sulfate (MIC>100㎍/ml)와 streptomycin sulfate (MIC>100㎍/ml)에도 저항성을 나타내었다.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2008년도 제49회 학술심포지움 및 국제학술대회
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• pp.65.1-65.1
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• 2008

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2008년도 제49회 학술심포지움 및 국제학술대회
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• pp.66.1-66.1
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• 2008

• 대한통합의학회지
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• 제11권4호
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• pp.125-133
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• 2023

Purpose : This study aimed to analyze the antibacterial activity of Liriope platyphylla ethanol extract (LPEE) against Streptococcus mutans and Porphyromonas gingivalis and to validate its potential for the prevention and treatment of dental caries, gingivitis, and periodontal disease. Methods : To verify the antibacterial effect of L. pulsatilla ethanolic extract (LPEE) against S. mutans and P. gingivalis, the disk diffusion method was used to determine the inhibition zones at concentrations of 50, 100, 200, and 300 mg/㎖. To determine the minimum inhibition concentration (MIC), the final dose of LPEE was .2, .4, .8, 1.6, 2.5, and 5.0 mg/㎖, and the minimum bactericidal concentration (MBC) was determined based on the MIC results. To confirm the growth inhibitory effect of LPEE on both pathogens, the absorbance was measured at 600 nm after each incubation for 0, 3, 6, 12, and 24 hr at concentrations of .8, 1.6, 2.5, and 5.0 mg/㎖. Results : The cytotoxicity of LPEE was evaluated and the cell viability was more than 70 % at 400 mg/㎖. Therefore, concentrations of 50, 100, 200, and 300 mg/㎖ were used in this study. The antimicrobial effect against S. mutans was seen at 100 mg/㎖ and grew in a concentration-dependent manner, while P. gingivalis was effective at 50 mg/㎖ with the dose dependency. The MIC was .8 mg/㎖ for both strains, and the MBC was 1.6 mg/㎖ with the same results. The growth inhibitory effect of LPEE on S. mutans and P. gingivalis was observed, even at low concentrations. Conclusion : The antibacterial effect of LPEE was evaluated through the analysis of MIC, MBC, and growth inhibition effect on S. mutans and P. gingivalis, which suggests LPEE might have the possibility of utilization as a preventive and therapeutic composition for oral diseases.

• Journal of Microbiology and Biotechnology
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• 제22권6호
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• pp.872-881
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• 2012

The inhibitory effect of the Klebsiella pneumoniae ATCC 13883 strain caused by the hexane extract of Halimeda discoidea (Nor Afifah et al., 2010) was further evaluated by means of the microscopy view and its growth curves. The morphological changes of the K. pneumoniae ATCC 13883 cells were observed under the scanning electron microscope (SEM) and transmission electron microscope (TEM) after they were treated at minimum inhibitory concentration (MIC; 0.50 mg/ml) (Nor Afifah et al., 2010) for 12, 24, and 36 h. The results showed the severity of the morphological deteriorations experienced by the treated cells. The killing curve assay was performed for 48 h at three different extract concentrations (1/2 MIC, MIC, and 2 MIC). An increase in the extract concentration of up to 2 MIC value did significantly reduce the number of cells by approximately 1.9 $log_{10}$, as compared with the control. Identification of the potential compounds of the extract responsible for the antibacterial activity was carried out through the gas chromatography-mass spectrum (GC-MS) analysis of the active subfraction, and the compound E-15-heptadecenal was identified and suggested as the most potential antibacterial compound of this extract. The subsequent cellular degenerations showed by the data might well explain the inhibitory mechanisms of the suggested antibacterial compound. All of these inhibitory effects have further proven the presence of an antibacterial compound within H. discoidea that can inhibit the growth of K. pneumoniae ATCC 13883.

• Journal of Microbiology and Biotechnology
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• 제34권3호
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• pp.538-546
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• 2024

Cinnamaldehyde is a natural compound extracted from cinnamon bark essential oil, acclaimed for its versatile properties in both pharmaceutical and agricultural fields, including antimicrobial, antioxidant, and anticancer activities. Although potential of cinnamaldehyde against plant pathogenic bacteria like Agrobacterium tumefaciens and Pseudomonas syringae pv. actinidiae causative agents of crown gall and bacterial canker diseases, respectively has been documented, in-depth studies into cinnamaldehyde's broader influence on plant pathogenic bacteria are relatively unexplored. Particularly, Pectobacterium spp., gram-negative soil-borne pathogens, notoriously cause soft rot damage across a spectrum of plant families, emphasizing the urgency for effective treatments. Our investigation established that the Minimum Inhibitory Concentrations (MICs) of cinnamaldehyde against strains P. odoriferum JK2, P. carotovorum BP201601, and P. versatile MYP201603 were 250 ㎍/ml, 125 ㎍/ml, and 125 ㎍/ml, respectively. Concurrently, their Minimum Bactericidal Concentrations (MBCs) were found to be 500 ㎍/ml, 250 ㎍/ml, and 500 ㎍/ml, respectively. Using RNA-sequencing analysis, we identified 1,907 differentially expressed genes in P. carotovorum BP201601 treated with 500 ㎍/ml cinnamaldehyde. Notably, our results indicate that cinnamaldehyde upregulated nitrate reductase pathways while downregulating the citrate cycle, suggesting a potential disruption in the aerobic respiration system of P. carotovorum during cinnamaldehyde exposure. This study serves as a pioneering exploration of the transcriptional response of P. carotovorum to cinnamaldehyde, providing insights into the bactericidal mechanisms employed by cinnamaldehyde against this bacterium.

• Journal of Microbiology and Biotechnology
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• 제24권8호
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• pp.1059-1064
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• 2014

Staphylococcus aureus is a major human pathogen, implicated in both community and hospital acquired infections. The therapy for methicillin-resistant Staphylococcus aureus (MRSA) infections is becoming more difficult because of multidrug resistance and strong biofilm-forming properties. Schiff bases have attracted attention as promising antibacterial agents. In this study, we investigated the in vitro activity of taurine-5-bromosalicylaldehyde Schiff base (TBSSB) against MRSA. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) were determined using a microtiter broth dilution method. TBSSB effectively inhibited planktonic MRSA, with an MIC of $32{\mu}g/ml$. The time-kill curve confirmed that TBSSB exhibited bactericidal activity against MRSA. TBSSB was also found to significantly inhibit MRSA biofilm formation at 24 h, especially at $1{\times}MIC$ and sub-MIC levels. Furthermore, scanning electron microscopy and transmission electron microscopy showed remarkable morphological and ultrastructural changes on the MRSA cell surface, due to exposure to TBSSB. This study indicated that TBSSB may be an effective bactericidal agent against MRSA.