• Title/Summary/Keyword: Antagonistic Inhibitory Effect

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Colony Count with Mixed Culture of Enteric Bacteria by in vitro Quantitative Method (장내세균의 시간차 혼합배양이 보여주는 균수측정의 비교)

  • 황선철;전보성
    • Korean Journal of Microbiology
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    • v.11 no.4
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    • pp.175-180
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    • 1973
  • This study was attempted to see more clear relationships among the enterobacteria, especially between the intestinal normal flora and pathogenic bacteria. It has been known that some intestinal normal flora produce the bactrial metabolites that are harmful to other enteric bacteria. One of the metabolites is known as colicin, the protein fraction, which possesses certain degree of inhibitory effect against other bacterial growth fraction, whih possesses certain degree of inhibitory effect against other bacterial growth. As a preliminary study for a colicin purification, the antagonistic effect of E, coli to groups of Salmonella and Shigella has been studied by means of in vitro quantitative culture method. 1. E.coli showed definite inhibitory effects aganist both Salmonella and Shigella groups in the mixture of two organisms. 2. The inhibitory effects of E.coli in the E.coli-Salmonella and the E.coli-Shigella mixture occurred from 4 hours incubation following the inoculation. 3. Even the complete inhibition of pathogenic enteric bacterial growth was noticed in the E.coli-Salmonella mixture at overnight incubation. 4. Among the diluted mixtures, 1:100, 1:1,000, and 1:10,000, survival rate of pathogenic enteric bacteria in the mixtures with E.coli showed least affected at the 1:1,000 dilution. 5. It was found that the antagonistic effect aganist groups of Salmonella-shigella was depending upon the groups of the genera.

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Studies on the inhibitory substance of yeast growth (Part II ) Effect on the nitrogen uptake (항효모성 물질에 관한 연구 (제II보) 질소대사와의 관계)

  • 서정훈;송방호;유춘발
    • Microbiology and Biotechnology Letters
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    • v.1 no.1
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    • pp.3-11
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    • 1973
  • The biochemical characteristics of Astradix -P, isolated from Astragalus membranaceus Bunge as yeaststatic substance, were reported on a previous paper. And on this report, some relation to the nitrogen metabolism of yeast was studied. Inorganic or organic source of nitrogen easily uptaking yeast did not show any antagonistic action to the inhibitory action of Astradix -P on the yeast growth. Especially an organic nitrogen source, arginine, histidine and lysine, classified to basic amino acid, was reacted as an antagonistic substance to the sample. But, ornithine, a basic amino acid, did not show any antagonistic action to the sample. In the mixed media containing neutral and acidic amino acids as a nitrogen source, yeast growth was inhibited strongly. If the basic amino acid was added to the same mixed media, the yeast growth was not inhibited by Astradix-P therefore, the antagonistic action of basic amino acid to the Astradix-p was readily observed. The yeast static action of Astradix-P was partially related to the isoelectric point of amino acid as a nitrogen source. Yeast cells which propagated under the media containing growth inhibitor, Astradix -p, did not bring any remarkable denaturation of cell structure by electro-microscopic observation.

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Biological Control of Powdery Mildew by Antibiotic-producing Microorganisms Antagonistic to Erysiphe graminis

  • Lee, Yong-Se;Wolf, G.
    • Journal of Microbiology and Biotechnology
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    • v.5 no.6
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    • pp.341-345
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    • 1995
  • Seventy four microorganisms, which have antagonistic activity against to Fusarium culmorum, were tested for their inhibitory effect on colony development of obligate biotroph Erysiphe graminis f. sp. hordei Marchal, the causal agent of powdery mildew on barley plants. Of these, 13 actinomycetes isolates were shown to reduce the colony development of mildew completely by application of their 10% cell-free culture filtrates on barley leaves. An Isolate, A252, was the most powerful antagonist and its antifungal activity was further assessed. The colony development of mildew was significantly reduced by application of the 1% cell-free culture filtrate of isolate A252. In comparison to the control, the protective and curative application of 10% cell-free culture filtrate from A252 showed 88.5% and 96.1% reduction of colony numbers respectively. By the protective application, 68.3% of the inhibition was observed after 9 days of treatment, thus showed prolonged inhibitory effect. In vitro test, complete inhibition of the mycelial growth of Microdochium nivale was achieved by the treatment of 1% A252 culture filtrate and 80.2% of inhibition was observed by the 0.1% treatment.

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Antagonistic inhibitory effects of probiotics against pathogenic microorganisms in vitro (Probiotics의 병원성미생물에 대한 길항적 억제효과)

  • Yuk, Young Sam;Lee, Young ki;Kim, Ga-Yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.12
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    • pp.110-116
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    • 2019
  • To investigate the antagonistic inhibitory effects in a mixed culture between probiotics and various pathogenic microorganisms, 140 probiotics were identified using a 16 rRNA sequencing phylogenetic analysis method, and various probiotics strains were isolated from Korean kimchi from January to December 2016. The antagonistic inhibition test of a mixed culture of four probiotics (Enterococcus faecalis, Lactobacillus plantarum, Lactobacillus rhamnosus, and Lactobacillus reuteri) with excellent antimicrobial activity and six pathogenic microorganisms (Candida albicans, Salmonella Enteritidis, E. coli O157:H7, Shigella flexneri, Staphylococcus aureus, and Pseudomonas aeruginosa)showed that the growth of most probiotics strains increased normally after culture, but growth was inhibited almost completely in most pathogenic microorganisms, except for S. Enteritidis. This antagonistic inhibitory effect in vitro was attributed to the low pH of the lactic acid and organic acid produced during fermentation. As a result, four probiotics strains isolated from Korean Kimchi are very likely to be developed as therapeutic agents for female yeast infections and colon and skin care. In the future, these therapeutic agents will help improve public health related to probiotics.

Antagonism against Helicobacter Pylori and Proteolysis of Lactobacillus Helveticus CU631 and Strain Identification

  • Yoon, Y.H.;Won, B.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.7
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    • pp.1057-1065
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    • 2002
  • The antagonistic activities of 30 strains of lactobacilli against Helicobacter pylori were determined and Lactobacillus helveticus CU631 has been selected as the strain which possesses the strongest inhibitory effect in the disc diffusion assay showing inhibition zone diameter of $10{\pm}1.5mm$, whereas those of L. plantarum and L. fermentum have been shown to be $4.0{\pm}0.6mm$. H. pylori G88016 revealed the highest vacuolating toxin producing activity among the 8 strains, the inhibitory activity of L. helveticus CU631 in vacuolating toxin producing activity of H. pylori manifested in the co-culture of two strains and in the 5:5 mixture of supernatant of the two strains. Both L. helveticus CU631 and cell free culture supernatant had a strong inhibitory activities in urease and cytotoxin producing activities of H. pylori NCTC11637 and CJH12. An accelerated proteolytic activity of water soluble peptides by L. helveticus CU631 during the refrigeration storage has been manifested in the cream cheese. DNA seqences of 16S-23S ribosomal RNA spacer region showed typical pattern among the various strains of L. helveticus, which could be used in the identification of L. helveticus CU 631.

Effect of Burkholderia contaminans on Postharvest Diseases and Induced Resistance of Strawberry Fruits

  • Wang, Xiaoran;Shi, Junfeng;Wang, Rufu
    • The Plant Pathology Journal
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    • v.34 no.5
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    • pp.403-411
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    • 2018
  • This study takes strawberry-fruits as the test material and discusses the effect of Burkholderia contaminans B-1 on preventing postharvest diseases and inducing resistance-related substances in strawberry-fruits. Soaking and wound inoculating is performed to analyze the inhibitory effects of different treatment solutions on the gray mold of postharvest strawberry-fruits. The count of antagonistic bacteria colonies in the wound is found, and the dynamic growth of antagonistic bacteria and the pathogenic fungus is observed by electron microscopy. The results indicated that, either by soaking/wound-inoculating, the fermentation and suspension of antagonistic bacteria significantly reduced the incidence of postharvest diseases of strawberry-fruits. With wound inoculation, the inhibition rate of antagonist fermentation and suspension ($1{\times}10^{10}cfu/ml$) respectively reached 77.4% and 66.7%. It also led to a significant increase in the activity of resistance-related enzymes, i.e., phenylalanine ammonia lyase (PAL), 4-coumarate coenzyme A ligase (4CL), cinnamate-4-hydroxylase (C4H) and chalcone isomerase (CHI). On 1 d and 2 d post-treatment, the activity of 4CL was respectively 3.78 and 6.1 times of the control, and on 5 d, the activity of PAL was increased by 4.47 times the control. The treatment of antagonistic bacteria delayed the peaking of cinnamyl-alcohol dehydrogenase (CAD) activity and promoted the accumulation of lignin and total phenols. The antagonistic bacteria could be well colonized in the wounds. On 4-5 d post-inoculation, the count of colonies was $10^8$ times of that upon inoculation. Electronmicroscopy indicated that the antagonistic bacteria delayed the germination of pathogenic spores in the wounds, and inhibited further elongations of the mycelia.

Studies on the Efficacy of Combined Preparation of Crude Drugs (XXIX) -Effects of Insamyangwee-tang on Gastrointestinal Tract- (생약(生藥) 복합(複合) 제제(製劑)의 약효(藥效) 연구(硏究)(제29보)(第29報) -인삼양위탕(人蔘養胃湯)이 위장관(胃腸管)에 미치는 영향(影響)-)

  • Hong, Nam-Doo;Jeong, Gyu-Man;Lee, Dong-Hyun;Joo, Soo-Man
    • Korean Journal of Pharmacognosy
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    • v.17 no.3
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    • pp.215-222
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    • 1986
  • Although the 'Insamyangwee-tang' has been widely used in clinical purposes in the oriental medicine, its clinical efficacy is only documentated for the cases of gastritis, gastric ulcer and enteritis, but the experimental study on these has not been undertaken. So, to investigate the clinical efficacy of 'Insamyangwee-tang' comparing with animal experiments, This study was carried out. The results showed that relaxing action was shown on the isolated ileum in mice and that strong antagonistic actions were seen on $BaCl_2$, acetylcholine and histamine induced contraction of the ileum in mice, rats, rabbits and guinea-pigs that the relaxing effect of the intestinal smooth muscle was recognized. Inhibitory effects on transport rate in the small intestine of mice. Strong antagonistic actions were seen on acetylcholine induced contraction of duodenum in rats and remarkably inhibiting actions were seen of duodenum in rats. Inhibitory action on the secretion of gastric juice and pepsin, anti-ulceration effect was recognized.

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Biological control of Botrytis cinerea on tomato using antagonistic bacteria

  • Hong, Sung-Jun;Kim, Yong-Ki;Jee, Hyeong-Jin;Park, Jong-Ho;Han, Eun-Jung;An, Nan-Hee;Kim, Jung-Hyun;Goo, Hyung-Jin
    • Korean Journal of Organic Agriculture
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    • v.19 no.spc
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    • pp.251-254
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    • 2011
  • Botrytis cinerea infects stems and leaves of greenhouse tomatoes and can cause serious economic losses. This study was conducted to develop environment-friendly control method against tomato gray mold. Antagonistic microorganisms (bacteria) were screened for control activity against Botrytis cinerea, both in vitro and in vivo, using stem sections. One hundred bacterial strains were isolated from the rhizospheric soil of various plants including tomato. These strains were screened for growth inhibition of Botrytis cinerea on agar plate by the dual culture and thirty strains showing strongly inhibitory effect against the pathogen were selected first. Among thirty strains, JB 5-12, JB 22-2, JB 22-3, U 4-8 and U46-6 reduced significantly disease incidence, when applied simultaneously with the pathogen. These results suggested that five antagonistic bacteria strains selected have the potential to control tomato gray mold in organic farming.

Bacterial Community of Traditional Doenjang in Longevity Area and Antagonistic Effect against Bacillus cereus (장수지역 전통된장의 미생물 군집 및 바실러스 세레우스 길항 효과)

  • Jeon, Doo-Young;Yoon, Gi-Bok;Yoon, Yeon-Hee;Yang, Soo-In;Kim, Jung-Beom
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.45 no.7
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    • pp.1035-1040
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    • 2016
  • This study investigated the prevalence of foodborne pathogens and the bacterial community of traditional Doenjang collected from a longevity area in Korea as well as the antagonistic effect of traditional Doenjang isolates against Bacillus cereus to estimate the microbiological safety of traditional Doenjang. Aerobic bacteria showed $10^6{\sim}10^9CFU/g$, whereas coliform bacteria was not detected. Foodborne pathogens were not detected except B. cereus, which was detected in seven samples out of 10 Doenjang samples. A total of 327 isolates were identified from traditional Doenjang. The isolates consisted of Bacillus subtilis 155 (47.4%), Bacillus licheniformis 68 (20.8%), Bacillus amyloliquefaciens 46 (14.1%), and Bacillus pumilus 18 (5.5%). Antagonistic effect against B. cereus was detected in 20 (6.1%) of 327 isolates, which consisted of B. subtilis (12 strains), B. amyloliquefaciens (5 strains), and B. licheniformis (3 strains). The inhibitory zone for the antagonistic effect was 9.0~12.0 mm in diameter. Although a small amount of traditional Doenjang was tested in this study, these results indicated that the potential risk of B. cereus in traditional Doenjang is lower than generally presumed. It is necessary to monitor the antagonistic effect of traditional Doenjang isolates against B. cereus.

Antibacterial Activity of Sophoraflavanone G Isolated from the Roots of Sophora flavescens

  • Cha, Jeong-Dan;Jeong, Mi-Ran;Jeong, Seung-Il;Lee, Kyung-Yeol
    • Journal of Microbiology and Biotechnology
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    • v.17 no.5
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    • pp.858-864
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    • 2007
  • This study investigated the antibacterial activities of sophoraflavanone G from Sophora flavescens in combination with two antimicrobial agents against oral bacteria. The combined effect of sophoraflavanone G and the antimicrobial agents was evaluated using the checkerboard method to obtain a fractional inhibitory concentration(FIC) index. The sophoraflavanone G+ampicillin(AM) combination was found to have a synergistic effect against S. mutans, S. sanguinis, S. sobrinus, S. gordonii, A. actinomycetemcomitans, F nucleatum, P. intermedia, and P. gingivalis, whereas the sophoraflavanone G+gentamicin(GM) combination had a synergistic effect against S. sanguinis, S. criceti, S. anginosus, A. actinomycetemcomitans, F nucleatum, P. intermedia, and P. gingivalis. Neither combination exhibited any antagonistic interactions(FIC index>4). In particular, the MICs/MBCs for all the bacteria were reduced to one-half$\sim$one-sixteenth as a result of the drug combinations. A synergistic interaction was also confirmed by time-kill studies for nine bacteria where the checkerboard suggested synergy. Thus, a strong bactericidal effect was exerted through the drug combinations, plus in vitro data suggested that sophoraflavanone G combined with other antibiotics may be microbiologically beneficial rather than antagonistic.