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1.
Microb Pathog ; 189: 106595, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38387848

RESUMO

Cymodocea serrulata mediated titanium dioxide nanoparticles (TiO2 NPs) were successfully synthesized. The XRD pattern and FTIR spectra demonstrated the crystalline structure of TiO2 NPs and the presence of phenols, flavonoids and alkaloids in the extract. Further SEM revealed that TiO2 NPs has uniform structure and spherical in shape with their size ranged from 58 to 117 nm. Antibacterial activity of TiO2 NPs against methicillin-resistant Staphylococcus aureus (MRSA) and Vibrio cholerae (V. cholerae), provided the zone of inhibition of 33.9 ± 1.7 and 36.3 ± 1.9 mm, respectively at 100 µg/mL concentration. MIC of TiO2 NPs against MRSA and V. cholerae showed 84% and 87% inhibition at 180 µg/mL and 160 µg/mL respectively. Subsequently, the sub-MIC of V. cholerae demonstrated minimal or no impact on bacterial growth at concentration of 42.5 µg/mL concentration. In addition, TiO2 NPs exhibited their ability to inhibit the biofilm forming V. cholerae which caused distinct morphological and intercellular damages analysed using CLSM and TEM. The antioxidant properties of TiO2 NPs were demonstrated through TAA and DPPH assays and exposed its scavenging activity with IC50 value of 36.42 and 68.85 µg/mL which denotes its valuable antioxidant properties with potential health benefits. Importantly, the brine shrimp based lethality experiment yielded a low cytotoxic effect with 13% mortality at 100 µg/mL. In conclusion, the multifaceted attributes of C. serrulata mediated TiO2 NPs encompassed the antibacterial, antioxidant and anti-biofilm inhibition effects with low cytotoxicity in nature were highlighted in this study and proved the bioderived TiO2 NPs could be used as a promising agent for biomedical applications.


Assuntos
Nanopartículas Metálicas , Staphylococcus aureus Resistente à Meticilina , Nanopartículas , Titânio , Antioxidantes/farmacologia , Antioxidantes/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Antibacterianos/farmacologia , Antibacterianos/química , Nanopartículas/química , Biofilmes , Nanopartículas Metálicas/química
2.
Arch Microbiol ; 205(8): 282, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37432479

RESUMO

In the present study, the individual cultures of Proteus mirabilis (P. mirabilis) and Klebsiella pneumoniae (K. pneumoniae) were treated with morphologically modified silver nanoparticles (Ag NPs) and were found to display zones of inhibition of ~ 8 mm, 16 mm, 20 mm, and 22 mm (P. mirabilis) and 6 mm, 14 mm, 20 mm, and 24 mm (K. pneumoniae) at concentrations of 25 µg/ml, 50 µg/mL, 75 µg/mL, and 100 µg/mL, respectively. In addition, turbidity tests were performed based on O. D. values, which exhibited 92% and 90% growth inhibitions at 100 µg/mL concentration for P. mirabilis and K. pneumoniae, respectively. Furthermore, the IC50 concentration of Ag NPs was established for A549 lung cancer cells and found to be at 500 µg/mL. Evidently, the morphological variation of Ag NPs treated A549 lung cancer cells was exhibited with differential morphology studied by phase-contrast microscopy. The results demonstrated that the synthesized Ag NPs was not only efficient against gram-positive bacteria but also against gram-negative bacteria and A549 cancer cells, suggesting that the potential of these biosynthesized Ag NPs is a future drug discovery source for inhibiting bacteria and cancer cells.


Assuntos
Neoplasias Pulmonares , Nanopartículas Metálicas , Humanos , Prata/farmacologia , Descoberta de Drogas , Klebsiella pneumoniae , Proteus mirabilis
3.
Curr Microbiol ; 80(8): 264, 2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37386175

RESUMO

Two novel bacterial strains, designated as SM33T and NSE70-1T, were isolated from wet soil in South Korea. To get the taxonomic positions, the strains were characterized. The genomic information (both 16S rRNA gene and draft genome sequence analysis) show that both novel isolates (SM33T and NSE70-1T) belong to the genus Sphingomonas. SM33T share the highest 16s rRNA gene similarity (98.2%) with Sphingomonas sediminicola Dae20T. In addition, NSE70-1T show 96.4% 16s rRNA gene similarity with Sphingomonas flava THG-MM5T. The draft genome of strains SM33T and NSE70-1T consist of a circular chromosome of 3,033,485 and 2,778,408 base pairs with DNA G+C content of 63.9, and 62.5%, respectively. Strains SM33T and NSE70-1T possessed the ubiquinone Q-10 as the major quinone, and a fatty acid profile with C16:0, C18:1 2-OH, C16:1 ω7c/C16:1 ω6c (summed feature 3) and C18:1 ω7c/C18:1 ω6c (summed feature 8) as major fatty acids. The major polar lipids of SM33T and NSE70-1T were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid and phosphatidylcholine, respectively. Moreover, genomic, physiological, and biochemical results allowed the phenotypic and genotypic differentiation of strains SM33T and NSE70-1T from their closest and other species of the genus Sphingomonas with validly published names. Therefore, the SM33T and NSE70-1T represent novel species of the genus Sphingomonas, for which the name Sphingomonas telluris sp. nov. (type strain SM33T = KACC 22222T = LMG 32193T), and Sphingomonas caseinilyticus (type strain NSE70-1T = KACC 22411T = LMG 32495T).


Assuntos
Sphingomonas , RNA Ribossômico 16S/genética , Sphingomonas/genética , Ácidos Graxos , Genômica , Genótipo
4.
Artigo em Inglês | MEDLINE | ID: mdl-37216283

RESUMO

Four novel bacterial strains, designated as RG327T, SE158T, RB56-2T and SE220T, were isolated from wet soil in the Republic of Korea. To determine their taxonomic positions, the strains were fully characterized. On the basis of genomic information (16S rRNA gene and draft genome sequences), all four isolates represent members of the genus Sphingomonas. The draft genomes of RG327T, SE158T, RB56-2T and SE220T consisted of circular chromosomes of 2 226 119, 2 507 338, 2 593 639 and 2 548 888 base pairs with DNA G+C contents of 64.6, 63.6, 63.0 and 63.1 %, respectively. All the isolates contained ubiquinone Q-10 as the predominant quinone compound and a fatty acid profile with C16 : 0, C17 : 1ω6c, C18 : 1 2-OH, summed feature 3 (C16 : 1ω7c/C16 : 1ω6c) and summed feature 8 (C18 : 1ω7c/C18 : 1ω6c) as the major fatty acids, supporting the affiliation of strains RG327T, SE158T, RB56-2T and SE220T to the genus Sphingomonas. The major identified polar lipids in all four novel isolates were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid and phosphatidylcholine. Moreover, the physiological, biochemical results and low level of DNA-DNA relatedness and average nucleotide identity values allowed the phenotypic and genotypic differentiation of RG327T, SE158T, RB56-2T and SE220T from other species of the genus Sphingomonas with validly published names and indicated that they represented novel species of the genus Sphingomonas, for which the names Sphingomonas anseongensis sp. nov. (RG327T = KACC 22409T = LMG 32497T), Sphingomonas alba sp. nov. (SE158T = KACC 224408T = LMG 324498T), Sphingomonas brevis (RB56-2T = KACC 22410T = LMG 32496T) and Sphingomonas hankyongi sp. nov., (SE220T = KACC 22406T = LMG 32499T) are proposed.


Assuntos
Ácidos Graxos , Sphingomonas , Ácidos Graxos/química , Fosfolipídeos/química , Análise de Sequência de DNA , RNA Ribossômico 16S/genética , DNA Bacteriano/genética , Composição de Bases , Filogenia , Técnicas de Tipagem Bacteriana , Espermidina/química
5.
Chemosphere ; 308(Pt 1): 136270, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36057355

RESUMO

Recent years, metal pollution is an alarming factor to know about protects the environmental ecosystem due to the toxic, persistent and abundant in nature. Metals are present everywhere in the biotic and abiotic samples including soil, water, and microbes. The rate of bioaccumulation and biotransformation are very high. The excess concentration of the metals causes heavy metal pollution or contamination. Due to these defects, the removal of metals using biological sources is heightened in the current research. In this current investigation, the biosorption potential ability of the metal tolerable Bacillus cereus on Pb and Cu rich environment was chosen and thoroughly monitored. The 16s rRNA of the Bacillus cereus was sequenced, and named as Bacillus cereus RMN 1 (MK521259). The various test concentration (10-60 mg/mL) of Pb and Cu was exhibited the maximum removal percentages of 85.2% and 60.2%. The result of bisorption factors exhibited, 300 mg/mL of the biosorbent potency, 60 min contact time and pH 7, and they found to be optimal to remove the maximum of Pb ion from the solution. In the regression coefficients, the Freundlich and Langmuir isotherm models were used to study the adsorption kinetics of metal ions. In addition, the isotherm model confirmed that the of B. cereus biomass medicated metal adsorption was more favourable reaction for metal degradation. With the above evidences, the results of the present investigation proved that B. cereus derived biomass was actively adsorbing the metals ions. Thus we are recommending for the implementation of effective waste water treatment.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Adsorção , Bacillus cereus/genética , Biomassa , Ecossistema , Concentração de Íons de Hidrogênio , Íons , Cinética , Chumbo , Metais Pesados/análise , RNA Ribossômico 16S , Solo , Poluentes Químicos da Água/toxicidade
6.
Anal Biochem ; 653: 114787, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35709929

RESUMO

Zinc (Zn) and, alternatively, nickel (Ni) substituted cobalt ferrite (CF) nanoparticles (NPs) were prepared by sol-gel method. X-ray diffraction analysis revealed the formation of cubic structure of cobalt ferrite. FTIR analysis confirmed the vibrational band located at 550-580 cm-1 that belongs to the M - O bond (M = Ni, and Zn). The alteration of the surface morphology of CF after the addition of Zn and Ni ions was observed from scanning electron microscopic images. The additional peaks in the energy dispersive X-ray diffraction (EDX) analysis spectra were found to correspond to Zn and Ni. The presence of Zn and, alternatively, Ni ions enhanced the biocidal properties of CF NPs against gram negative organisms, in a concentration and time-dependent manner. Furthermore, exposure to CF, CF-Zn and CF-Ni NPs decreased metabolic activity due to the damage of extra polymorphic substances, live/dead cell variation, architecture and surface integrity of the cells. Altogether, the present investigation provides the basis of metal ion substituted metal oxide NPs as anti-biofilm agents against gram-positive and gram-negative bacteria.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Antibacterianos/química , Antibacterianos/farmacologia , Cobalto/química , Compostos Férricos , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Nanopartículas Metálicas/química , Nanopartículas/química , Níquel/química , Óxidos/química , Difração de Raios X , Zinco/química
7.
Environ Res ; 212(Pt B): 113310, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35472466

RESUMO

This study looked at the development of effective biosorbents to recover the most toxic elements from industrial water. B. amyloliquefaciens was isolated from marine soils showing extreme resistance to Chromium (Cr(VI)) ions. During the 60 min of contact time, 79.90% Cr(VI) was adsorbed from the aqueous solution. The impact of important factors such as biomass concentration, pH of the medium, and initial metal ions concentration on biosorption rate was also examined. The desorption study indicated that 1 M HCl (91.24%) was superior to 0.5 M HCl (74.81%), 1 M NaOH (64.96%), and distilled water (3.66%). Based on the Langmuir model, the maximum adsorption capacity of the bio-absorbent was determined to be 48.44 mg/g. The absorption mechanism was identified as monolayer, and 1/n from the Freundlich model falls within 1, thus indicating favorable adsorption. Based on the findings of the present study, the soil bacterium B. amyloliquefaciens was found to be the best alternative and could be used to develop strategies for managing existing environmental pollution through biosorption.


Assuntos
Bacillus amyloliquefaciens , Poluentes Químicos da Água , Adsorção , Bactérias , Biomassa , Cromo/análise , Concentração de Íons de Hidrogênio , Íons , Cinética , Solo , Água , Poluentes Químicos da Água/análise
8.
Environ Res ; 204(Pt A): 111914, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34437851

RESUMO

In this work, graphene oxide-p-Phenylenediamine nanocomposites of two different ratios of Graphene oxide: p-Phenylenediamine (1:1 and 1:5) were prepared and characterized by using analytical, spectroscopic and microscopic studies (GO-pPD 11 and GO-pPD 15). These nanocomposites were employed as fluorescent chemosensors for sensing potential cations. Remarkably, graphene oxide-p-Phenylenediamine nanocomposites of ratio 1:1 (GO-pPD 15) was selective and sensitive to Ag+ ions, whereas the graphene oxide-p-Phenylenediamine nanocomposites of ratio 1:5 (GO-pPD 15) was selective to Ce3+ions. A possible mechanism as switch "off-on" is proposed built on the inhibition of the photo induced electron transfer process in both the fluorescent probes in detecting the metal ions. In addition, interference studies were performed with the help of competitive complexation analysis and no significant interference were found by other potentially competing cations. The pH studies revealed that both the chemosensors can be used at the physiological pH for the ion detection and also the detection time was within 2-3 min. Both the chemosensors show good reversibility and hence the sensors can be used for multiple times. The newer nanocomposites were then utilized in the real water sample analysis as to check its real level application purpose.


Assuntos
Grafite , Nanocompostos , Íons , Fenilenodiaminas
9.
Environ Res ; 204(Pt C): 112337, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34742711

RESUMO

Recent years, heavy metal reduction of contaminated atmosphere using microbes is heightened worldwide. In this context, the current study was focused on heavy metal resistant actinomycete strains were screened from effluent mixed contaminated soil samples. Based on the phenotypic and molecular identification, the high metal resistant actinomycete strain was named as Nocardiopsis dassonvillei (MH900216). The highest bioflocculent and exopolysaccharide productions of Nocardiopsis dassonvillei (MH900216) was confirmed by various invitro experiments result. The heavy metal degrading substances was characterized and effectively confirmed by Fourier transform infrared spectroscopy (FT-IR), X-Ray Diffraction (XRD), Scanning electron microscope (SEM). Further, the heavy metal sorption ability of actinomycete substances bioflocculent was exhibited 85.20%, 89.40%, 75.60%, and 51.40% against Cd, Cr, Pb and Hg respectively. Altogether, the bioflocculent produced actinomycete Nocardiopsis dassonvillei (MH900216) as an excellent biological source for heavy metal reduction in waste water, and it is an alternative method for effective removal of heavy metals towards sustainable environmental management.


Assuntos
Metais Pesados , Águas Residuárias , Adsorção , Metais Pesados/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Águas Residuárias/química
10.
Saudi J Biol Sci ; 28(11): 6057-6062, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34759735

RESUMO

Based on the excellent nutrient level, the current study was focused on isolation and anti-bacterial activity of the actinomycetes from marine mangrove soil samples. As result, 10 different strains of actinomycetes strains were identified on actinomycetes isolation agar plates. The identified strains were shown with white, clear, uncontaminated well matured spore producing ability. Based on the initial observation, the isolated colonies were actinomycetes. The partially extracted crude compound shown excellent anti-bacterial activity against P. aeruginosa and K. pneumoniae with 15 mm and 13 mm zone of inhibitions were observed at 500 µL concentrations. The minimum inhibition concentration result was also confirmed the 500 µL concentration against both the tested concentration with high inhibition rate. Then, the intracellular damages, decreased cell growth of the crude actinomycetes extract treated bacterial strains were clearly observed by confocal laser scanning electron microscope. The extracellular damages of bacterial cell wall and shape of the both the pathogens were clearly shown by scanning electron microscope. Therefore, all the results were clearly supported to the partially extracted crude compound and it has excellent anti-bacterial activity against tested multi drug resistant bacteria.

11.
J Infect Public Health ; 14(12): 1911-1916, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34785167

RESUMO

BACKGROUND: Recent years, the treatment of multi-drug resistant bacteria and their effect are very difficult due to the virulence factors modification. Based on the world wide thread, we have tried to identify the ESBLs producing bacteria from urinary tract infection patients. In result, the highly antibiotic resistant effect of Pseudomonas aeruginosa and Klebsiella pneumoniae were identified. METHODS: Initially, Hexa disc diffusion method was performed to detect the multi-drug resistant bacteria using respective antibiotics of HX066, HX033 and HX077, HX012 discs. Consecutively, the ESBL producing ability of confirmed multi drug resistant bacteria was performed to detect their ESBL producing ability using specific extended spectrum beta lactamase (ESBLs) detection discs of Hexa G-minus 24. Furthermore, the ESBL producing ability of the bacteria was confirmed by ESBLs detection Ezy MIC™ E-test stripe method. RESULTS AND CONCLUSIONS: In result, 10, 5 and 4 mm and 10, 14 and 8 mm zone of inhibition against imipenem (IPM), Ticarcillin/Clavulanic acid (TCC), Cefoperazone (CPZ) and Ampicillin (AMP), Norfloxacin (NX), Nalidixic acid (NA) antibiotics for P. aeruginosa and 16, 22 and 10, 18 mm zone of inhibition against ceftazidime (CAZ), methicillin (MET), ampicillin amoxyclav (AMC), co-trimoxazole (COT) of the HX077 HX012 for K. pneumoniae were observed. Based on the Clinical & Laboratory Standards Institute (CLSI) guidelines, both the bacteria were more resistant to tested antibiotics and it could be developed more resistant against all the tested antibiotics. In addition, the phenotypic detection of ESBL production effect was also performed against both the selected uropathogens, and the results were shown ≥22 mm, ≥27 zone of inhibition against all the tested antibiotics. Further, the genetic identification of multi plux PCR result was shown TEM, SHV and CTX-m genes were present in both the selected uropathogens. Finally, our results were correlated each other and concluded that the selected uropathogens were multi drug resistant effect and also ESBLs producer.


Assuntos
Infecções Urinárias , beta-Lactamases , Antibacterianos/farmacologia , Bactérias/genética , Humanos , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana , beta-Lactamases/genética
12.
Environ Res ; 200: 111708, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34280417

RESUMO

The removal of toxic heavy metal ions from contaminated environments is a great challenge and requires an alternative rapid, efficient, economical bioremediation approach. Henceforth, bioflocculant producing endophytic actinobacterial sp. was isolated from heavy metal contaminated marine environments for heavy metal biosorption process. After molecular characterization, the isolated actinomycete starin was Nocardiopsis sp. GRG 3 (KT235642). It was indicated that the maximum flocculating activity of 80.90% with glucose, and yield is 4.52 g L1. The optimum flocculating activity was reached at pH 7 in the presence of CaCl2 ions. Further, the bioflocculent produced Nocardiopsis sp. GRG 3 (KT235642) was characterized by fourier transform infrared analysis spectra (FTIR) and displayed the presence of carboxyl, hydroxyl, amino groups and characteristic of more polysaccharide and protein. The heavy metal sorption by bioflocculant Nocardiopsis sp. GRG 3 (KT235642) was effectively removed 55.90% Cd, 85.90% Cr, 74.7% Pb, and 51.90% Hg. Therefore, this study was proved that the bioflocculant derived from endophytic actinobacteria, Nocardiopsis sp. GRG 3 (KT235642) as a effective alternative method for decreasing the heavy metals towards sustainable environmental management.


Assuntos
Actinobacteria , Metais Pesados , Actinomyces , Biodegradação Ambiental , Floculação , Concentração de Íons de Hidrogênio
13.
Environ Res ; 199: 111322, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34019895

RESUMO

Heavy metal pollution in the water bodies causes a serious threat to all living beings. Extended exposure of heavy metals such as nickel (Ni) ions causes cancer. Henceforth, the current study investigated the removal of Ni ions from the electroplating effluent using nanocomposites namely, Graphene Oxide (GO) and Reduced Graphene Oxide (rGO) in the presence of various factors such as contact time, pH, agitation speed and sorbent dosage. Further, it was determined the rate kinetic model and adsorption equilibrium isotherms. The study also focused on comparing the removal efficiency of two nanocomposites. The maximum sorption efficiency were found to be 90.8% and 84.4% at optimized pH (8), contact time (180-1440 m), RPM (250-300) and adsorbent dosage (0.2 mg/L) for GO and rGO respectively. Furthermore, toxicity of treated and untreated effluent were tested against Phosphobacter and Azospirillium using GO and rGO and found that the treated effluent was non-toxic. The contribution of this study to agriculture in using recycled effluent for crop cultivation was being verified by seed germination of Lablab purpureus seeds watered with treated and untreated effluent. Finally we concluded that the results of treated water can be used for cultivation as there was healthy growth of plants.


Assuntos
Níquel , Poluentes Químicos da Água , Adsorção , Galvanoplastia , Grafite , Íons , Cinética , Poluentes Químicos da Água/análise
14.
Saudi J Biol Sci ; 28(3): 1750-1756, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33732058

RESUMO

The multi-drug resistant effect of the Gram negative bacteria K. pneumoniae was identified by disc diffusion method using specific UTI panel discs of Kleb 1 HX077 and Kleb 2 HX090 HEXA. Among the multi-drug resistant bacteria, the carbapenem resistant (CR) effect of the K. pneumoniae was screened by specific carbapenem detection antibiotics of HEXA HX066 and HX0103 HEXA by disc diffusion method. In addition, the effective antibiotics were further performed against K. pneumoniae by minimum inhibition concentration method. Further, the carbapenemase genes of VIM 1 and IMP 1 were detected from the isolated strains by multiplex PCR method. Furthermore, the biofilm forming ability of selected carbapenem resistant K. pneumoniae was initially identified by tissue culture plate method and confirmed by exopolysaccharide arrest ability of congo red agar assay. Finally, our result was proved that the identified K. pneumoniae is carbapenemase producing strain, and its virulence was extended with strong biofilm formation.

15.
Saudi J Biol Sci ; 28(3): 1763-1769, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33732060

RESUMO

In this study, the phytochemical, phenolic, flavonoid and bioactive compounds were successfully screened from crude extract of Sargassum wightii by LC-MS analysis after NIST interpretation. Bacterial growth inhibition study result was shown with 24 mm zone inhibition at 200 µg/mL concentration against P. aeruginosa. The increased phenolic content was much closed to gallic acid and the range was observed at 250 µg/mL concentration. In addition, flavonoid contents of the algae extract was indicated more significant with rutin at 200 µg/mL. In result, both the phenolic and flavonoid contents of the extract were more correlated with gallic acid and rutin. Further, the total anti-oxidant and DPPH radical scavenging activities were shown increased activity at 200 µg/mL concentrations. Furthermore, the excellent anti-bacterial alteration result was observed at 200 µg/mL concentration by minimum inhibition concentration. Therefore, the result was revealed that the marine algae Sargassum wightii has excellent phytochemical and anti-oxidant activities, and it has improved anti-bacterial activity against P. aeruginosa.

16.
Colloids Surf B Biointerfaces ; 202: 111690, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33721803

RESUMO

In the present study, chitosan-containing nanocomposites were investigated as new antibacterial agents. Magnetite (Fe3O4) nanoparticles (NPs) as well as chitosan (CS)/Fe3O4 nanocomposites (NCs) and graphene(Gr)/CS/Fe3O4 NCs were synthesized by simple hydrothermal method. Their composition, structure and morphology were studied, followed by the evaluation of their antibacterial activity against ESBL-producing and gram-negative P. aeruginosa and K. pneumoniae bacterial strains. The Gr/CS/Fe3O4 NCs showed significantly higher antibacterial activity compared to Fe3O4 NPs and CS/Fe3O4 NCs (105 and 69 % higher against P. aeruginosa as well as 91 and 77 % higher against K. pneumoniae, respectively). The minimum inhibitory concentration (MIC) of Gr/CS/Fe3O4 NCs against P. aeruginosa and K. pneumoniae were 60 and 70 µg/mL, respectively. The synergistic antibacterial activity and facile synthesis of Gr/CS/Fe3O4 NCs suggests their applicability as novel highly efficient antibacterial agents with potential for a wide range of biomedical applications, where antibacterial properties are needed.


Assuntos
Quitosana , Grafite , Nanocompostos , Antibacterianos/farmacologia , Óxido Ferroso-Férrico , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa
17.
Chemosphere ; 273: 129681, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33517117

RESUMO

Silica nanoparticles are generally mesoporous that are predominant in the sand and rocks. Silica nanoparticles have a wide range of applications in various fields such as medicine, waste management, effluent treatment and electronics. The present work has explored the synthesis of silica nanoparticles through acid and alkaline leaching method from Pedalium murex which is a common weed that is found in southern parts of Tamil Nadu. Silica nanoparticles (SiNps) and its functional groups were confirmed by EDX and FTIR analysis with their respective energy dispersion levels and wavenumbers. Size, shape and morphological features of SiNps were analysed by PSA, TEM and SAED analysis. Synthesised and characterized nanosilica was crosslinked over nylon-66 and cellulose nitrate membranes and were confirmed by FTIR analysis for their crosslinking with SiNps. Water retention activity of the crosslinked and non crosslinked membranes was analysed by contact angle measurement to ensure the receptability of the membranes to remove contaminants by the adsorption. The decolourisation efficiency of the crosslinked nylon 66 membrane was found as a potential source for the treatment with 65.5% colour reduction when compared with other membranes. A slight reduction of solid profiles and COD ranges were achieved for crosslinked membranes than non crosslinked membranes.


Assuntos
Nanopartículas , Purificação da Água , Índia , Dióxido de Silício , Têxteis
18.
Saudi J Biol Sci ; 27(12): 3421-3427, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33304151

RESUMO

The Caulerpa taxifolia is excellent marine green algae, which produced enormous bioactive compounds with more biological activities. Also, it is an excellent source for synthesis of Ag NPs with increased bioactivity against various infections. In our study, the marine algae marine algae Caulerpa taxifolia mediated Ag NPs was synthesized effectively. The synthesized Ag NPs was characterized well using UV-spectrometer and X-ray powder diffraction (XRD) and confirmed as synthesized particle was Ag NPs. The available structure of the Ag NPs was morphologically identified by scanning electron microscope (SEM), and exact minimum size, polydispersive spherical shape of the entire Ag NPs structure was confirmed by Transmission electron microscope (TEM). Further, the anti-cancer efficiency of biosynthesized Ag NPs against A549 lung cancer cells was found at 40 µg/mL concentration by cytotoxicity experiment. In addition, the phase contrast images of the result were supported the Ag NPs, which damaged the A549 morphologically clearly. Finally, florescence microscopic images were effectively proved the anti-cancerous effect against A549 lung cancer cells due to the condensed morphology of increased death cells. All the confirmed in-vitro results were clearly stated that the Caulerpa taxifolia mediated Ag NPs has superior anti-cancer agent against A549 lung cancer cells.

19.
Saudi J Biol Sci ; 27(11): 3018-3024, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33100861

RESUMO

The biosynthesized Ag NPs was synthesized by using marine mangrove plant extract Avicennia marina. The synthesized Ag NPs was confirmed by various physiochemical characterization including UV-spectrometer and XRD analysis. In addition, the shape and of the synthesized Ag NPs was morphologically identified by SEM initially and TEM finally. After confirmation, the anti-cancer property of synthesized Ag NPs was confirmed at 50 µg/mL concentration against A549 lung cancer cells by MTT assay. Further, the ability to stimulate the ROS generation and mitochondrial membrane at the IC50 concentration of Ag NPs was confirmed by fluorescence microscopy using DCFH-DA and rhodamine 123 dyes respectively. Finally, the result was concluded that the synthesized Ag NPs has improved anti-cancer activity against A549 cells at lowest concentration.

20.
Mater Sci Eng C Mater Biol Appl ; 114: 111024, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32994001

RESUMO

In this study, silver nanoparticles (Ag NPs) was eco-friendly synthesized using purified flavonoid rich content of Morinda citrifolia (M. citrifolia) extract. The synthesized Ag NPs was exhibited at 420 nm in UV-spectrometer, and surface morphology with available chemical composition, shape and size of the Ag NPs were confirmed by X-ray diffraction (XRD) variation, scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX) and transmission electron microscope (TEM). In addition, the excellent phytochemicals and anti-oxidant activity of the Ag NPs were confirmed by total anti-oxidant and DPPH free radical scavenging assays. Further, the concentration dependent inhibition of synthesized Ag NPs against biofilm forming Staphylococcus aureus (S. aureus) was confirmed by minimum inhibition concentration (MIC). The growth cells were arrested in the log phase of the culture and detected by flow cytometry analysis. In addition, the bacterial viability, exopolysaccharide degradation, intracellular membrane damage, matured biofilm inhibition, architectural damage and morphological alteration were confirmed by confocal laser scanning electron microscope (CLSM) and SEM. Furthermore, the synthesized Ag NPs reacted with methylene blue (MB) dye molecules has 100% degradation at an irradiation time of 140 min. Conclusively, the eco-friendly synthesized Ag NPs has excellent anti-oxidant, anti-bacterial through intracellular membrane damage, cell cycle arrest and methylene blue dye removal.


Assuntos
Nanopartículas Metálicas , Staphylococcus aureus Resistente à Meticilina , Antibacterianos/farmacologia , Extratos Vegetais/farmacologia , Prata , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus , Staphylococcus saprophyticus , Difração de Raios X
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