scholarly journals Removal of the antimicrobial activity from fortified effluents with fluoroquinolones by photocatalytic processes: a comparative study of differently synthesized TiO2-N

Author(s):  
Wilson Augusto Lima Venancio ◽  
Caio Rodrigues-Silva ◽  
Mylena Spina ◽  
José Roberto Guimarães

Abstract This study presents a comparison of three methods for TiO2-N synthesis that were applied in the photocatalytic oxidation of the fluoroquinolones (FQs) ciprofloxacin, ofloxacin, and lomefloxacin in aqueous solution. The TiO2-N bandgap is small enough to allow the use of solar energy in the photocatalytic oxidation (PCO) reactions. The TiO2 doped by a sol-gel method with titanium butoxide (TiO2–N–BUT) and titanium isopropoxide (TiO2–N–PROP) as the precursor were effective as the TiO2 (P25) impregnation with urea (TiO2-N-P25) to degrade the FQs. The FQ degradation was higher by 74, 65, and 91%, respectively for TiO2–N–BUT, TiO2–N–PROP, and TiO2-N (load 50 mg L−1, 20 min of reaction under 28 W UV-ASolar). The TiO2-P25 with urea showed the best performance in FQ degradation. The reaction intermediates might present modifications in their acceptor groups by PCO and, because of that the antimicrobial activity dropped as the reaction time increased. Reactions with TiO2-N-P25 (100 mg L−1) and TiO2-N-BUT (100 mg L−1) achieved ≥ 80% of antimicrobial activity removal from the mixed FQ solution (Cciprofloxacin = 100 μg L−1; Cofloxacin = 100 μg L−1; Clomefloxacin = 100 μg L−1) after 40 min of reaction, for both for Escherichia coli and Bacillus subtilis.

Author(s):  
Nitesh Parmar ◽  
Jitendra Kumar Srivastava

Abstract This study is an attempt to the removal of Ciprofloxacin (CIP) antibiotic from simulated wastewater using a photocatalytic process. The photocatalytic process was carried out in a photocatalytic reactor in the presence of TiO2 nanoparticles. TiO2 nanoparticles were successfully prepared in a laboratory scale using sol-gel method with titanium-isopropoxide (TTIP) as titanium precursor. Prepared material was found very effective to the removal of CIP antibiotic. The maximum removal efficiency of 87.95% of ciprofloxacin from aqueous solution was achieved at the pH 5, catalyst doze of 40 mg L−1 with initial concentration of ciprofloxacin 5 mg L−1, and the reaction time of 100 min additionally; material characterization of TiO2 was presented in detail in terms of XRD, SEM, UV, and FTIR. It has been found that at the optimum condition the total operating cost indicated for the removal of ciprofloxacin from aqueous solution is 786.56 (INR/kg of CIP removal). This technique demonstrated that photocatalytic reaction in presence of TiO2 nanoparticles is well applicable to treat pharmaceutical wastewater.


2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Julieta Cabrera ◽  
Dwight Acosta ◽  
Alcides López ◽  
Roberto J. Candal ◽  
Claudia Marchi ◽  
...  

TiO2 nanotubes were synthesized by alkaline hydrothermal treatment of TiO2 nanoparticles with a controlled proportion of anatase and rutile. Tailoring of TiO2 phases was achieved by adjusting the pH and type of acid used in the hydrolysis of titanium isopropoxide (first step in the sol-gel synthesis). The anatase proportion in the precursor nanoparticles was in the 3–100% range. Tube-like nanostructures were obtained with an anatase percentage of 18 or higher while flake-like shapes were obtained when rutile was dominant in the seed. After annealing at 400°C for 2 h, a fraction of nanotubes was conserved in all the samples but, depending on the anatase/rutile ratio in the starting material, spherical and rod-shaped structures were also observed. The photocatalytic activity of 1D nanostructures was evaluated by measuring the deactivation of E. coli in stirred water in the dark and under UV-A/B irradiation. Results show that in addition to the bactericidal activity of TiO2 under UV-A illumination, under dark conditions, the decrease in bacteria viability is ascribed to mechanical stress due to stirring.


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.


2018 ◽  
Vol 13 (4) ◽  
pp. 1934578X1801300
Author(s):  
Daniyar Sadyrbekov ◽  
Timur Saliev ◽  
Yuri Gatilov ◽  
Ivan Kulakov ◽  
Roza Seidakhmetova ◽  
...  

A cyclopropane derivative of limonene, (1 S, 4 S, 6 R)-7,7-dichloro-4-[(1 S)-2,2-dichloro-1-methylcyclopropyl]-1-methylbicyclo [4.1.0] heptane (compound 2), was synthesized and its structure was determined by NMR and X-ray crystallographic methods. In addition, an antimicrobial activity of the compound against Gram-positive ( Staphylococcus aureus, Bacillus subtilis) and Gram-negative ( Escherichia coli, Pseudomonas aeruginosa) bacterial strains was also scrutinized.


Medicina ◽  
2008 ◽  
Vol 44 (12) ◽  
pp. 977 ◽  
Author(s):  
Alvydas Pavilonis ◽  
Algirdas Baranauskas ◽  
Ligita Puidokaitė ◽  
Žaneta Maželienė ◽  
Arūnas Savickas ◽  
...  

Objective. To evaluate the antimicrobial activity of soft and purified propolis extracts. Study object and methods. Antimicrobial activity of soft and purified propolis extracts was determined with reference cultures of Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 33499, Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis ATCC 12459, Bacillus subtilis ATCC 6633, Bacillus cereus ATCC 8035, and fungus Candida albicans ATCC 60193. Microbiological tests were performed under aseptic conditions. Minimum inhibitory concentration (MIC) – the highest dilution of preparation (the lowest concentration of preparation) that suppresses growth of reference microorganisms – was determined. Results. Concentration of phenolic compounds in soft propolis extract that possesses antimicrobial activity against gram-positive (Staphylococcus aureus, Enterococcus faecalis) and gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis) is 0.587±0.054 mg and 0.587±0.054–0.394±0.022 mg (P>0.05) and in purified propolis extract – 0.427±0.044 mg and 0.256±0.02 mg (P>0.05). Klebsiella pneumoniae is most resistant to soft propolis extract when the concentration of phenolic compounds is 1.119± 0.152 mg and to purified propolis extract when the concentration of phenolic compounds is 1.013±0.189 mg (P>0.05). Spore-forming Bacillus subtilis bacteria are more sensitive to soft and purified propolis extracts when the concentration of phenolic compounds is 0.134±0.002 mg and 0.075±0.025 mg, respectively, and Bacillus cereus – when the concentration is 0.394±0.022 mg and 0.256±0.02 mg (P>0.05). Sensitivity of fungus Candida albicans to soft and purified propolis extracts is the same as Bacillus subtilis. Encapsulated bacterium Klebsiella pneumoniae is most resistant to antimicrobial action of soft and purified propolis extracts as compared with gram-positive Staphylococcus aureus and Enterococcus faecalis bacteria (P<0.05), gram-negative Escherichia coli, Pseudomonas aeruginosa, and Proteus mirabilis (P<0.05), sporeforming Bacillus subtilis and Bacillus cereus bacteria (P<0.05), and fungus Candida albicans (P<0.05). There is no statistically significant difference between antimicrobial effect of soft propolis extract and purified propolis extract on gram-positive bacteria, gram-negative bacteria, spore-forming bacteria, encapsulated bacteria, and Candida fungus. Conclusions. Soft and purified propolis extracts possess antimicrobial activity. They could be recommended as natural preservatives in the manufacture of pharmaceutical products.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Agnieszka Maria Jastrzębska ◽  
Ewa Karwowska ◽  
Andrzej R. Olszyna ◽  
Antoni R. Kunicki

The present paper provides comparative assessment of antimicrobial efficiency of ionic silver (Ag+), silver monoxide (Ag2O), and metallic silver (Ag) incorporated onto an aluminum oxide nanopowder carrier (Al2O3). The deposition of Ag+ ions, Ag2O nanoparticles, and Ag nanoparticles on an different phases of aluminum oxide nanopowder carrier was realized using consecutive stages of dry sol-gel method. The Al2O3-Ag+, Al2O3-Ag2O, and Al2O3-Ag nanopowders were widely characterized qualitatively and quantitatively by SEM, physical nitrogen sorption and XRD analyses. Results indicate that the Al2O3 nanopowders added with Ag+, Ag2O, and Ag, apart from phase composition, were not differing considerably from one another in terms of their morphology and physical properties. However, nanopowders of Al2O3-Ag were more agglomerated than Al2O3-Ag2O and Al2O3-Ag+ nanopowders. The antibacterial activity of the nanopowders was examined by the spread plate method using bacterial strains such as Escherichia coli, Sarcina lutea, and Bacillus subtilis. The best antibacterial properties against Sarcina lutea strain were achieved in the amorphous-Al2O3-Ag+ and Al2O3-Ag2O nanopowders, whereas the worst antimicrobial activity against Bacillus subtilis and Escherichia coli was shown by the Al2O3-Ag+ and Al2O3-Ag nanopowders. The observed increase of the antibacterial activity as the silver content was not however significant for Al2O3-Ag nanopowders. The results obtained in the present experiments show that the Al2O3-Ag+, Al2O3-Ag2O, and Al2O3-Ag nanopowders, possessing good bactericidal properties, can be produced by using consecutive stages of dry sol-gel method, and Al2O3 nanopowder added with Ag2O is considered as the best raw material in the production of antiseptic materials.


2020 ◽  
Vol 1 (2) ◽  
pp. 41-45
Author(s):  
A.Suparlan Isya Syamsu

Preliminary research has been conducted on the antimicrobial activity of n-Butanol extract of forest honey (Apis nigrocincta). This study aims to determine the antimicrobial activity of forest honey from Selayar Regency on the growth of test microbes, using the method of solid dilution with the test microbial Bacillus subtilis, Staphylococcus aureus, Streptococcus mutans, Pseudomonas aeruginosa, Salmonella typhi, Escherichia coli, Vibrio sp, Staphylococcus epidermidis, and Candida albicans against n-butanol extract from forest honey (Apis nigrocincta) at 1 mg/ml. The results obtained showed that n-butanol extract inhibited the growth of bacteria Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus aureus. To estimate the compounds that provide antimicrobial activity, the TLC-Bioautography test is performed. Obtained the best results from the separation of compounds by TLC using Chlorophorom eluate: Acetone (3: 1). The TLC-Bioautographic test results showed that the spots with an Rf value of 0.29 gave activity to Bacillus subtilis, Escherichia coli, and Staphylococcus epidermidis, and gave positive results on the appearance of flavonoid compounds.


2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Dhiraj Dutta ◽  
Swagata Goswami ◽  
Rama Dubey ◽  
Sanjai K. Dwivedi ◽  
Amrit Puzari

Abstract Background Growing microbial resistance towards the existing antimicrobial materials appears as the greatest challenge for the scientific community and development of new antimicrobial materials has become an important research objective. Results In this work, antimicrobial activity of silver-coated hollow poly(methylmethacrylate) microspheres (PMB) having a diameter of 20–80 µm was evaluated against two bacterial strains, Gram-positive Bacillus subtilis (MTCC 1305) and Gram-negative Escherichia coli (MTCC 443). The polymeric PMMA microspheres were synthesized by solvent evaporation technique and were further coated with silver (Ag) under microwave irradiation on their outer surface using an electroless plating technique. It was observed that Ag was uniformly coated on the surface of microspheres. Characterization of the coated microspheres was performed using optical microscope (OMS), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), UV–Vis spectroscopy, FTIR spectroscopy and thermogravimetric analysis (TGA) techniques. We have shown that the silver-coated microspheres were potent bactericidal material for water as they are highly active against the tested microorganisms. The results of the antibacterial tests indicated that APMB particles showed enhanced inhibition rate for both Gram-positive and Gram-negative bacteria and also exhibited dose-dependent antibacterial ability. The diameters of zone of inhibition were14.3 ± 0.2 mm against B. subtilis and 15.2 ± 0.9 mm against E. coli at a concentration of 8 mg. At this concentration, total removal of both Bacillus subtilis and Escherichia coli was observed. The results of shake flask technique for a concentration of 8 mg showed no bacterial presence after 24 h in both the cases. In other words, the material acted efficiently in bringing down the bacterial count to zero level for the tested strains. During the experiments, we have also confirmed that use of this material for water disinfection does not cause leaching of silver ion in to the water solution. The material can be successfully regenerated by backwashing with water. Conclusions Considering the cost-effective synthesis, ability to regenerate and very low level of leaching of the material, it can be projected as an advanced material for water disinfection and antimicrobial application.


2018 ◽  
Vol 20 (1) ◽  
pp. 8-15 ◽  
Author(s):  
Shanti Ratnakomala ◽  
Nurul Fitri Sari ◽  
Fahrurrozi Fahrurrozi ◽  
Puspita Lisdiyanti

AbstractA total of 98 actinomycetes were isolated from the soil and litter samples collected from the cacao and coffee plantation in Lombok Island, West Nusa Tenggara, Indonesia. These isolates were screened for their antimicrobial activity. Among 98 isolated strains, only 24 isolates showed antimicrobial activity against test microorganisms of which 20.4% were active against Bacillus subtilis BTCC B-612, 14.3% against Staphylococcus aureus BTCC B-611, and 5.1% against Escherichia coli BTCC B-609. Out of these 24 isolates, 3 were found to be able to grow in medium containing 3 mM Selenium oxide of which the culture were changed color to red. Two of the best strains, L-155 and L-156, were selected for assessing production of Selenium nanoparticles. Bioreduction of selenium nanoparticles was confirmed by UV–visible spectrophotometer which showed peak between 300 and 320 nm. Biosynthesized selenium nanoparticle from isolate actinomycetes L-155 and L-156 were found to have a broad spectrum of activity against the tested microorganisms: Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Micrococcus luteus, and Candida albicans. This study showed rapid and eco-friendly synthesis of selenium nanoparticles from soil actinomycetes. Most of these active isolates revealed to possess antibacterial property.


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