scholarly journals ANTAGONISTIC ACTIVITY OF ACTINOMYCETES ISOLATED FROM SALINE SOILS NEAR WITH KUMISI LAKE (GEORGIA)

Author(s):  
M. D. Tsulukidze ◽  
Z. Sh. Lomtatidze ◽  
Q. H. Mamulashvili

Aim. To study the antagonistic activity of actinomycetes isolated from soils adjacent to Kumisi Lake (Georgia). Methods. It was used 12 samples of actinomycetes isolated from the soils adjacent to Kumisi Lake. The antibiotic activity of actinomycetes was determined using test strains: Escherichia coli К-12 (B-3254), Bacillus subtilis 26 D, Xanthomonas campestris В-1459, Rhizobium radiobacter C58, Pectobacterium carotovorum EC1by the method of agar blocks. Results. It was revealed that actinomycete samples isolated from soils adjacent to Lake Kumisi shown the most significant inhibitory effect on test strains: Escherichia coli B-3254, Rhizobium radiobacter C58 and Xanthomonas campestris В-1459. The most resistant test-strains, to the studied actinomycetes, were Bacillus subtilis 26 D and Pectobacterium carotovorum EC1. Conclusion. Isolated strain 301 of actinomycetes shown a significant antagonistic effect on all test strains and could be potential for further studies spectrum and properties of antibiotic compounds.

2018 ◽  
Vol 8 (2) ◽  
pp. 354-364
Author(s):  
A. N. Irkitova ◽  
A. V. Grebenshchikova ◽  
A. V. Matsyura

<p>An important link in solving the problem of healthy food is the intensification of the livestock, poultry and fish farming, which is possible only in the adoption and rigorous implementation of the concept of rational feeding of animals. In the implementation of this concept required is the application of probiotic preparations. Currently, there is an increased interest in spore probiotics. In many ways, this can be explained by the fact that they use no vegetative forms of the bacilli and their spores. This property provides spore probiotics a number of advantages: they are not whimsical, easily could be selected, cultivated, and dried. Moreover, they are resistant to various factors and could remain viable during a long period. One of the most famous spore microorganisms, which are widely used in agriculture, is <em>Bacillus subtilis</em>. Among the requirements imposed to probiotic microorganisms is mandatory – antagonistic activity to pathogenic and conditional-pathogenic microflora. The article presents the results of the analysis of antagonistic activity of collection strains of <em>B. subtilis</em>, and strains isolated from commercial preparations. We studied the antagonistic activity on agar and liquid nutrient medias to trigger different antagonism mechanisms of <em>B. subtilis</em>. On agar media, we applied three diffusion methods: perpendicular bands, agar blocks, agar wells. We also applied the method of co-incubating the test culture (<em>Escherichia coli</em>) and the antagonist (or its supernatant) in the nutrient broth. Our results demonstrated that all our explored strains of <em>B. subtilis</em> have antimicrobial activity against a wild strain of <em>E. coli</em>, but to varying degrees. We identified strains of <em>B. subtilis</em> with the highest antagonistic effect that can be recommended for inclusion in microbial preparations for agriculture.</p><p><em><br /></em><em></em></p>


2020 ◽  
Vol 49 (4) ◽  
pp. 415-423
Author(s):  
B. Baráti-Deák ◽  
Cs. Mohácsi-Farkas ◽  
Á. Belák

Bacterial strains with inhibitory effect on Salmonella Hartford, Listeria monocytogenes, Yersinia enterocolitica, and Escherichia coli, respectively, were isolated. Out of the 64 bacteria originated from food processing environments, 20 could inhibit at least one of the tested pathogens, and it was proved that growth decline of the pathogenic bacteria was more remarkable by co-culturing than by using cell-free supernatants of the isolates. Seven different genera (Pseudomonas, Bacillus, Paenibacillus, Macrococcus, Staphylococcus, Serratia, and Rothia) reduced the pathogens’ growth during the time period of analysis, and the strongest inhibitory effect was observed after 24 h between 15 and 30 °C. Sensitivity of the tested human pathogenic bacteria against the inhibitory strains was distinct, as Y. enterocolitica could be inhibited by numerous isolates, while S. Hartford proved to be the most resistant. Our results reveal that the isolated bacteria or their excreted metabolites could hinder pathogen growth when used in sufficient quantities.


Author(s):  
Kokkaiah Irulandi ◽  
Sethupandian Geetha ◽  
Palanichamy Mehalingam

Objective: To determine antimicrobial activity of methanol, ethyl acetate and acetone extracts of Myristica fatua, Alstonia boonei, Helicteres isora, Vitex altissima and Atalantia racemosa  against different species of pathogens, Streptococcus feacalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Bacillus subtilis, Staphyllococcus aureus, and Candida albicans.Methods: Antimicrobial activity of plant extracts was measured by agar well diffusion method.Results: Acetone extracts of Alstonia boonei showed the highest inhibitory effect against Escherichia coli (21.00 ± 1.00 mm) and Streptococcus faecalis (19.00 ± 1.00 mm). All the extracts of Heliteres isora leaves showed different zone of inhibition observed in all the tested pathogens ranges between (8.13 ± 1.53 – 15.25 ± 1.23 mm). Ethyl acetate extract of Vitex altissima showed highest activity against Bacillus sublilis (19.67 ± 1.53 mm). Methanol and acetone leaves extracts of Atalantia racemosa have good fungal activity against the Candida albicans (19.33 ± 1.26 mm - 16.00 ± 1.00 mm). Methanol extract of Myristica fatua showed high antimicrobial activity against Pseudomonas aeruginosa (15.10 ± 0.17 mm) and Bacillus subtilis (14.23 ± 0.21 mm).Conclusion: The results from the study suggest that the leaves Myristica fatua, Alstonia boonei, Helicteres isora, Vitex altissima and Atalantia racemosa showed good antimicrobial activity against the different pathogens. They are used as the alternative source for the control and treatment of microbial infections.Keywords: Antimicrobial activity, Leaves extracts,  Well diffusion method, Pathogenic strains.


2021 ◽  
Vol 251 ◽  
pp. 02061
Author(s):  
Xiaojuan Gao ◽  
Xiaoshi Lu ◽  
Zifeng Wang ◽  
Guangpeng Liu ◽  
Xinjun Li

Taking monascin as the research object, monascin was extracted from red kojic rice by ethanol extraction and extracted with 60%, 70% and 80% ethanol respectively. Finally, it was concluded that when the concentration of ethanol was 70%, the extraction rate of monascin was the highest, reached 75.68%. The bacteriostatic experiments of monascin extract and monascin fermentation showed that it had strong inhibitory effect on Staphylococcus aureus and Bacillus subtilis, weak inhibitory ability on Escherichia coli and Aspergillus niger, and no obvious inhibitory effect on the growth of Saccharomyces cerevisiae.


2019 ◽  
pp. 58-62
Author(s):  
V. S. Rusaleyev ◽  
О. V. Pruntova ◽  
D. A. Vasilyev

A decrease in therapeutic effect of some live lacto- and bifdobacteria-based drugs for veterinary use has been observed for the last 20 years that urges scientists to search for new microorganisms possessing probiotic properties. Many studies in this feld are focused onBacillus subtilisthat is widespread in the environment and non-pathogenic for animals and humans. Results of tests ofBacillus subtilisfor its biological properties and antagonistic activity aimed at optimization of methodical approaches for detection of strain with the highest antagonistic effect on some opportunistic microorganisms and their further use as probiotics are described. Cultural morphological and biochemical characteristics of the tested strains conformed to the species characteristics ofBacillus subtilis.Tested strains were nonpathogenic for white mice. Tests showed that spore biomass could be prepared both in liquid and on solid nutrient media. Methodically, spore biomass preparation in liquid nutrient medium is preferable. The tests showed that spores emerged from anabiosis non-uniformly and it depended on original seed spore storage period. Spore cultures stored less than one year emerged from anabiosis more quickly. It was found that the spores formed more readily when the cultures were aerated with oxygen as well as that lag-phase culture medium had a stimulating effect onBacillus subtilisspore germination.Bacillus subtilisstrains were found to have antagonistic effect onEscherichia coli, SalmonellaandStaphylococcus. Area of growth inhibition of the said bacteria was 15–20 mm. TestedBacillus subtilisstrains could be proposed for use as probiotics.


2020 ◽  
Vol 46 (4) ◽  
pp. 253-263
Author(s):  
B. R. O. Omidiwura ◽  
A. F. Agboola ◽  
A. O. Adekambi

In effort to combat environmental pollution, improve animal production and avoid drug residue, producers have resorted to the use of phytobiotics to inhibit ammonia producing microbes in the gut. Freshly harvested Azadirachta indica, Carica papaya, Saccharum officinarum, Chromolaena odorata, Eucalyptus camadulensis and Mangifera indica leaves were air dried, blended and extracted using five concentrations of solvent (100% water, 70% water + 30% methanol, 50% water + 50% methanol, 30% water + 70% methanol and 100% methanol). The antibacterial activities of the extracts and antibiotics (doxycycline) as control, were tested according to standard procedures against both gram positive (Bacillus subtilis, Staphylococcus aureus) and gram negative (Escherichia coli, Vibrio cholerae) ammonia producing bacteria. In most cases, it was observed that the inhibitory effect of methanolic extracts of Azadirachta indica, Carica papaya, Saccharum officinarum, Chromolaena odorata, Eucalyptus camadulensis and Mangifera indica leaves were not significantly different from that of synthetic antibiotics, doxycycline, when tested against the test bacteria, Bacillus subtilis, Staphylococcus aureus and Vibrio cholera. However, leave extracts showed significantly better inhibitory effect on Escherichia coli than the antibiotic drug. It can be concluded, therefore, that the leaf extracts of Azadirachta indica, Carica papaya, Saccharum officinarum, Chromolaena odorata, Eucalyptus camadulensis and Mangifera indica can serve as alternative to synthetic drugs in animal production due to their effective actions against microbial organisms.


2020 ◽  
Vol 66 (6) ◽  
pp. 401-412
Author(s):  
Qingrong Li ◽  
Sentai Liao ◽  
Junhong Wei ◽  
Dongxu Xing ◽  
Yang Xiao ◽  
...  

Fusarium wilt is a devastating soil-borne disease mainly caused by highly host-specific formae speciales of Fusarium spp. Antagonistic microorganisms play a very important role in Fusarium wilt control. Isolation of potential biocontrol strains has become increasingly important. Bacterial strain SEM-2 was isolated from the high-temperature stage of silkworm excrement composting. SEM-2 exhibited a considerable antagonistic effect against Fusarium graminearum mycelial growth and spore germination. The results of pot experiments suggested that SEM-2 has a better inhibitory effect on the early stage of disease occurrence. The green fluorescent protein labelled SEM-2 coated on the surface of tomato seeds colonised the roots of tomato plants in 15 days. Genome sequencing identified SEM-2 as a new strain of Bacillus subtilis, and genome annotation and analysis determined gene clusters related to the biosynthesis of antimicrobials, such as bacillaene, fengycin, bacillibactin, subtilosin A, surfactin, and bacilysin. Interestingly, liquid chromatography – quadrupole time-of-flight mass spectrometry revealed that metabolites in pathways associated with the synthesis of secondary metabolites and antibiotics were highly differentially expressed. These findings may help to explain the mode of action of B. subtilis SEM-2 against Fusarium spp.


2009 ◽  
Vol 6 (4) ◽  
pp. 627-632
Author(s):  
Baghdad Science Journal

In this part of programme , different bacterial isolates mainly Salmonella spp, Shigella spp and Escherichia coli were used for antagonism with Saccharomyces boulardii under different conditions . S.boulardii was grown under aerobic conditions and antagonized with young overnight nutrient broth cultures of test bacterial isolates and other kept in refrigerator for a week after full growth . Young cultures were more susceptible to antagonistic effect of yeast compared to old cultures and on isolates grown on solid medium for 24 hr. S.boulardii grown under aerobic and microaerobic conditions and antagonized with overnight broth cultures of test bacterial isolates , The results revealed that aerobic cultures of yeast had more inhibitory effect on test isolates .Concentration of yeast cells from liquid media GS( prepared from soluble fraction of gluten and mixed with equal volume of corn steep water and GS2%) was found not to be exceeded 109 yeast cell/ ml of suspension due to the large size of yeast cells .Effect of freezing on viability of yeast cells grown in GS and GS2% was negligible and there was no significant differences since the difference was less then half log cycle


1994 ◽  
Vol 57 (1) ◽  
pp. 59-61 ◽  
Author(s):  
GERHARD J. HAAS ◽  
RAFFI BARSOUMIAN

The antimicrobial activity of hop resins against Streptococcus salivarius, Staphylococcus aureus (two strains), Bacillus megaterium, Escherichia coli B, and Bacillus subtilis was investigated. However, resistance development was carried out on Streptococcus salivarius, Staphylococcus aureus (two strains), and Bacillus megaterium. The two hop resins used were iso-alpha resin and beta resin. Prior to resistance development, S. salivarius, S. aureus, and B. megaterium were all inhibited by the iso-alpha-hop resin in the 0.01 to 0.03% range. The beta-hop resin which, according to the literature, is more active than the iso-alpha resin initially inhibited these organisms at the 0.003 to 0.01% concentrations. The ease of resistance development varied between the different microbes, B. megaterium being the least prone to develop resistance.


Sign in / Sign up

Export Citation Format

Share Document