scholarly journals Characterization of Micrococcus luteus and Bacillus marisflavi Recovered from Common Dentex (Dentex dentex) Larviculture System

2015 ◽  
Vol 17 (1) ◽  
pp. 163 ◽  
Author(s):  
T. AKAYLI ◽  
G. ALBAYRAK ◽  
Ç. ÜRKÜ ◽  
Ö. ÇANAK ◽  
E. YÖRÜK

In this manuscript, thirty yellow-pigmented Gram-positive bacteria were isolated from natural intestine microflora and from sea water around the marine cage of a rearing tank of common dentex (Dentex dentex), in the Aegean Sea on the Turkish coast and were characterized. Eighteen isolates were assigned to the species Micrococcus luteus, the other twelve to the species Bacillus marisflavi. Eight representative strains, six from B. marisflavi and two from M. luteus, were chosen for further 16S rDNA analyses. A pathogenicity assay for the isolated bacterial strains was carried out in rainbow trout and it evidenced absence of pathogenicity in the tested strains. The isolated strains were tested for in vitro antagonistic activity against Listonella anguillarum, a pathogen bacterium diffused in Mediterranean aquaculture and affecting various fish species. The isolated bacterial strains showed antagonistic activity against the pathogenic bacterium, suggesting a possible role of isolates as probiotics. In this study, for the first time, bacterial strains of the species B. marisflavi, known as an environmental species, were recovered in the gut microbiota of a healthy fish. The use of the isolates characterized in this study, mainly the yellow-pigmented bacterium, is suggested as possible probiotics to improve fish health, along with alternative methods of maintaining a healthy environment.

2021 ◽  
Vol 9 (5) ◽  
pp. 974
Author(s):  
Marc-Kevin Zinn ◽  
Marco Singer ◽  
Dirk Bockmühl

Although malodour formation on textiles and in washing machines has been reported to be a very relevant problem in domestic laundry, the processes leading to bad odours have not been studied intensively. In particular, the smell often described as “wet-and-dirty-dustcloth-like malodour” had not been reproduced previously. We developed a lab model based on a bacterial mixture of Micrococcus luteus, Staphylococcus hominis, and Corynebacterium jeikeium, which can produce this odour type and which might allow the detailed investigation of this problem and the development of counteractions. The model uses bacterial strains that have been isolated from malodourous textiles. We could also show that the three volatile compounds dimethyl disulfide, dimethyl trisulfide, and indole contribute considerably to the “wet-fabric-like” malodour. These substances were not only found to be formed in the malodour model but have already been identified in the literature as relevant malodourous substances.


2009 ◽  
Vol 4 (1) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Branislava Lakušić ◽  
Violeta Slavkovska ◽  
Milica Pavlović ◽  
Marina Milenković ◽  
Jelena Antić Stanković ◽  
...  

The essential oils of the aerial parts and fruits of Chaerophyllum aureum L., collected from two mountains in Serbia, were analyzed by GC and GC/MS. Sabinene (18.5-31.6%), p-cymene (7.9-25.4%) and limonene (1.9-10.9%) were characterized as the main constituents. The oils were tested against six bacterial strains and one strain of yeast, Candida albicans. The highest antimicrobial activity was observed against the Gram-positive bacteria Staphylococcus aureus, S. epidermidis and Micrococcus luteus, while of the Gram-negative strains, Escherichia coli was the most sensitive.


2010 ◽  
Vol 75 (6) ◽  
pp. 739-747 ◽  
Author(s):  
Dinesh Bisht ◽  
Rajendra Padalia ◽  
Lalit Singh ◽  
Veena Pande ◽  
Priyanka Lal ◽  
...  

The essential oils from six Himalayan Nepeta species, viz. Nepeta leucophylla Benth., Nepeta discolor Royle ex Benth., Nepeta govaniana Benth., Nepeta clarkei Hook f., Nepeta elliptica Royle ex Benth. and Nepeta erecta Benth., were tested for their in vitro antimicrobial activity against six pathogenic bacterial and two fungal strains. The results showed that Pseudomonas aeruginosa was the most sensitive strain tested to the essential oils of Nepeta species. The essential oils of N. elliptica and N. erecta exhibited the highest activity against P. aeruginosa, followed by the essential oils of N. leucophylla and N. clarkei. The essential oils from N. elliptica and N. erecta were also found to be very effective against Serratia marcescens; while the essential oil from N. leucophylla displayed significant activity against Proteus vulgaris and Staphylococcus aureus. Other bacterial strains displayed variable degree of susceptibility against one or more of the tested essential oils. The essential oil from N. leucophylla also showed the highest antifungal activity against both tested fungal strains, viz. Candida albicans and Trichophyton rubrum, followed by the essential oils from N. clarkei, N. govaniana and N. erecta. Iridodial derivatives, viz. iridodial ?-monoenol acetate (25.4 %), dihydroiridodial diacetate (18.2 %) and iridodial dienol diacetate (7.8 %) were identified as the major constituents of N. leucophylla, while the essential oils from N. elliptica and N. erecta were dominated by (7R)-trans, trans nepetalactone (83.4 %) and isoiridomyrmecin (66.7 %), respectively. The essential oil of N. discolor was characterized by 1,8-cineole (25.5 %) and ?-caryophyllene (18.6 %), while N. clarkei was dominated by ?-sesquiphellandrene (22.0 %) and germacrene D (13.0 %). Isoiridomyrmecin (35.2 %) and pregeijerene (20.7 %) were identified as the major constituents of N. govaniana. In general the Nepeta species containing constituents with an iridoid or lactone skeleton were found to have the greater antagonistic activity against most of the microbial strains as compared to those containing regular terpene constituents.


2020 ◽  
Vol 35 (1-2) ◽  
Author(s):  
Prashakha J. Shukla ◽  
Vishwa R. Vyas

Alang, ship breaking yard situated on north-west edge of Gulf of Khambhat. It is famous for ship breaking yard and contains very harmful heavy metals. Lead contamination is highest in Alang. To decrease the concentration of heavy metals many different physical, chemical and biological methods are available but they are harmful to nature and waste more quantity of chemicals. So, bioremediation is the best method to remove pollutants. A low concentration of heavy metals is required to plant for their growth and metabolic process but at higher concentration, plants do not survive. With the use of microbes, we can survive plants at certain levels. During this work, heavy metal tolerating microorganism was isolated from sea water of Alang and purified. Various tests were performed for identification and primary screening. in vitro examination in the different plants like moong, wheat, peanut, kidney beans and mat beans under 500ppm Pb concentration.


This article reflects the results of a study on the selection of promising lactobacilli antagonistic to Campilobacter jejuni, a strain that is the most common and more pathogenic for humans, carried out as part of a project to scientifically substantiate the use of new technologies in poultry feeding using special probiotic strains that increase productivity and obtaining poultry products of improved quality with the properties of functional food products. During the study, strains of lactic acid bacteria were obtained. The cultivation of strains of Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus fermentum, Lactobacillus reuteri, Lactobacillus plantarum, Lactobacillus plantarum was carried out on liquid and agarized nutrient media MRS at 370С for 24 hours. In vitro antagonistic studies were performed using the two-way antagonistic method on a wide range of indicator crops. Since there is evidence of a specific mechanism for the manifestation of the antagonistic activity of lactobacilli to gram-negative and gram-positive bacteria, we used test strains of both groups of bacteria. The antagonistic activity of the studied cultures against pathogenic and opportunistic bacteria was determined by the zone of growth inhibition of indicator strains around the colonies of individual strains of lactobacilli and their consortium (in mm). Priority clinical isolates isolated from birds with intestinal infections were used as indicator cultures: Proteus vulgaris, Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, Campylobacter jejuni and Campylobacter jejuni ATCC strains 33560. During the study, most bacterial strains of the genus Lactobacillus were highly antagonistic its activity against indicator strains. The most sensitive to the inhibitory effect of lactobacilli were E. coli, Campylobacter jejuni, S. typhimurium and P. vulgaris. The research results showed that the strain L.plantarum ATCC 8014 exhibits a more pronounced antagonistic activity than other strains of lactobacilli.


2020 ◽  
Vol 7 (1) ◽  
pp. 26-32
Author(s):  
Bendella Amina nor elhouda ◽  
Ghazi Kheira ◽  
Meliani Samia

AbstractThe aim of this study is to test two different methods for evaluating the in vitro antibacterial effect of Thymus fontanesii Boiss. et Reut. essential oil against standard and clinical bacterial strains responsible for bovine mastitis: the disc diffusion method or the aromatogram which allows the demonstration of the antibacterial power of essential oils on the bacterial strains tested, Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923 and two strains isolated from bovine mastitis milk S. aureus and E. coli. The inhibition activity of the essential oil of T. fontanesii on bacterial strains by the two methods shows that the antimicrobial power of this oil is very important and is characterized by bactericidal and bacteriostatic action against gram negative and gram positive bacteria. The antimicrobial evaluation by the aromatogram showed good antibacterial activity against all the strains tested, the zones of inhibition of the bacteria were between 23,33±1,527mm and 37,5±3,535 mm. The search for minimum inhibitory concentrations MIC and bactericides CMB made it possible to quantitatively assess the antimicrobial power of this essential oil. In this work, the MIC was 0,625 µl/ml for all strains tested, and the lowest CMB was that of T. fontanesii against E. coli ATCC 25922 was 0,625 µl/ml.


2020 ◽  
Vol 5 (4) ◽  
pp. 283-291
Author(s):  
Shraddha P. Mishra ◽  
Anfal Arshi ◽  
Ankur Agarwal ◽  
Merwyn P. Raj ◽  
Madhu Bala

In this study, we have aimed to determine the antagonistic effects of various rhizobacteria against representatives of bacterial wilt disease; Ralstonia pseudosolanacearum with a comparison from control sterile distilled water (SDW) aliquots. During in-vitro study, bacterial wilt agent was clearly inhibited in their growth by significant percentage by 32 different strains through perforated agar plate method. Results showed 10 potential strains among those 32 strains viz. DIB76/BCS-8, DIB76/BCS-9, DIB76/BCS-10, DIB76/BCS-12, DIB76/BCS-19, DIB76/BCS-20, DIB76/BCS-21, DIB76/BCS-24, DIB76/BCS-26 and DIB76/BCS-27 had the highest growth suppression for 9 different strains of R. pseudosolanacearum as compared to other bacterial strains. Trials with tomato crop at polyhouse had no incidence of bacterial wilt than those for control. Study, thus identifies 10 rhizobacterial strains from rhizosphere soil of diseased tomato plant possessing potential antagonistic activity against the wilt pathogen and has prospects as good biocontrol agents.


Author(s):  
Haïfa Debbabi ◽  
Ridha El Mokni ◽  
Ibrahim Jlassi ◽  
Rajesh K Joshi ◽  
Saoussen Hammami

Abstract Chemical composition and antimicrobial activity of Teucrium capitatum L. subsp. lusitanicum essential oil was investigated for the first time in the present study. Qualitative and quantitative analyses of the chemical composition by gas chromatography and mass spectrometry (GC–FID and GC–MS) revealed the presence of 60 compounds representing 97.6% of the whole constituents. The main compounds were germacrene D (47.1%), spathulenol (5.8%), α-selinene (5.3%), germacrene A (2.9%), δ-cadinene (2.8%) and cubenol (2.7%). In vitro, the antimicrobial activity was investigated against five bacterial strains along with the yeast Candida albicans using broth microdilution assay. T. capitatum subsp. lusitanicum essential oil showed significant activity against the gram-positive bacteria Staphylococcus aureus (MIC = MBC = 78 μg mL−1), Bacillus subtilis (MIC = MBC = 156 μg mL−1) and the yeast C. albicans (MIC = MFC = 156 μg mL−1). The great potential of antimicrobial effects is most likely due to the very high percentage of sesquiterpene hydrocarbons particularly to germacrene D, for which the antimicrobial properties have been previously reported.


2020 ◽  
Vol 11 ◽  
pp. 71-78
Author(s):  
Prof. Teodora P. Popova

Studies have been conducted to determine the antibacterial effect of Oxidal® and anolyte against Staphylococcus aureus and Escherichia coli. The bacterial strains tested showed high sensitivity to the dietary supplement Oxidal® and to anolyte, as well as to the control antibiotic Thiamphenicol. The mean MPC50 values of Oxidal® for Gram-positive bacteria S. aureus (0.21 ± 0.13 mg/ml) were lower than those for Gram-negative E. coli (0.55 ± 0.24 mg/ml). The dose that fully suppressed S. aureus growth was 0.86 ± 0.52 mg/ml, while for E. coli this dose was significantly higher - 2.40 ± 0.80 mg/ml (P<0.05). For the antibiotic Thiamphenicol, the results were opposite - the mean MPC50 values for E. coli (2.40 ± 0.80) were lower than those for S. aureus (3.71 ± 2.86). Under the influence of 10% Oxidal® solution, the amount of viable S. aureus and E. coli decreased by more than 30% over the untreated control after 20 min. After 45 minutes, only 37% of S. aureus cells and 19% of E. coli cells developed upon cultivation, and after 90 minutes of exposure, about 20% of the cells of the microorganisms understudy of both species remained viable. The fresh anolyte and the one stored for 1 year inactivated S. aureus and E. coli for 2 min in a suspension at a density of 106 cells/ml.


2020 ◽  
Vol 7 (4) ◽  
pp. 215-226
Author(s):  
Muhammad Rizwan Khan ◽  
Mohsin Abbas Khan ◽  
Khalil Ahmad ◽  
Asad Hamad ◽  
Muhammad Sajid-ur-Rehman ◽  
...  

Objective: Nowadays antibacterial drugs resistance is major problem in the world. To overcome this problem, some novel derivates of doxycycline were synthesized by single step condensation reaction with ten different types of aromatic and aliphatic aldehydes and ketones in ethanol as solvent and acetic acid as catalyst. In these reactions, deprotonation of primary amine occurs that results in formation of imine.  Methods: All the derivatives physically characterized and confirmed by analytical techniques i.e. FTIR and 1H NMR and 13C NMR. The derived compounds have exhibited significantly more active against both gram positive as well as gram negative bacterial strains as compared to parent drug. Results: Derived Schiff bases RDC2, RDC4 and RDC10 showed zone of inhibition against Bacillus subtilis as compared to doxycycline and derived Schiff bases RDC1, RDC2, RDC5, RDC6, RDC7 and RDC8 showed more zone of inhibition against Micrococcus luteus as compared to doxycycline. Yield (75%), m.p. 180-185°C, Mol. Wt. 1063, Elemental Analysis: (Calculated) for C58H54N4O16: iC, 65.53; H, 5.12; N, 5.27; (Found): C, 65.49; H, 5.18; N, 5.37; FTIR (ν, cm‐1): 3066 (=C-H), 1665(C=N), 1585, 1490(C=C, phenyl), 3650(OH), 1692 (C=O); 1H NMR (DMSO−d6, δ, ppm), 6.02-6.03 d, 6.91-6.92 d, (=CH-); 6.88-6.89 t (=CH), 2.89-2.90 d, (-CH); 1.07-1.08 q, (-CH3), 3.38-3.39 d; 3.17-3.18 d, (CH), 1.47-1.48 t (CH), 1.48 s, (CH3), 6.96-6.97d, 7.577-7.588 d, (-CH=) 15.21 s (OH); 4.62 s (OH); 1.46-1.47 s (OH); 13C NMR (DMSO−d6, δ, ppm). Conclusion: Doxycycline is among broad-spectrum tetracycline. The Schiff bases derived from doxycycline show significantly highly active against gram negative bacteria as compared to doxycycline. In future further study on these derived compounds will help in market new derivative of doxycycline, which will have more broad-spectrum activity than doxycycline.


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