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1.
Environ Res ; 251(Pt 2): 118698, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38518906

RESUMO

Sixty-eight morphologically distinct isolates of marine actinomycetes were derived from seashore, mangrove, and saltpan ecosystems located between the Palk Strait and Gulf of Mannar region, Bay of Bengal, Tamilnadu. Twenty-five (36.8%) isolates exhibited anti-mycotic activity against Candida albicans and Cryptococcus neoformans in preliminary screening, and 4 isolates with prominent activity were identified and designated at the genus level as Streptomyces sp. VPTS3-I, Streptomyces sp. VPTS3-2, Streptomyces sp. VPTSA1-4 and Streptomyces sp. VPTSA1-8. All the potential antagonistic isolates were further characterized with phenotypic and genotypic properties including 16S rRNA gene sequencing and identified species level as Streptomyces afghaniensis VPTS3-1, S. matensis VPTS3-2, S. tuirus VPTSA1-4 and S. griseus VPTSA1-8. In addition, the active fractions from the potential antagonistic streptomycetes were extracted with organic solvents by shake flask culture method and the anti-mycotic efficacies were evaluated. The optimization parameters for the production of the anti-mycotic compound were found to be pH between 7 and 8, the temperature at 30ᵒC, the salinity of 2%, incubation of 9 days, and starch and KNO3 as the suitable carbon and nitrogen sources respectively in starch casein medium.


Assuntos
Antifúngicos , Streptomyces , Índia , Streptomyces/genética , Streptomyces/metabolismo , Antifúngicos/farmacologia , Microbiologia do Solo , Candida albicans/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Baías/microbiologia , RNA Ribossômico 16S/genética
2.
J Environ Manage ; 351: 119674, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38061098

RESUMO

The proliferation of emerging pollutants (EPs), encompassing a range of substances such as phthalates, phenolics, pharmaceuticals, pesticides, personal care products, surfactants, and disinfection agents, has become a significant global concern due to their potential risks to the environment and human well-being. Over the past two decades, numerous research studies have investigated the presence of EPs in wastewater and aquatic ecosystems, with the United States Environmental Protection Agency (USEPA) categorizing these newly introduced chemical compounds as emerging contaminants due to their poorly understood impact. EPs have been linked to adverse health effects in humans, including genotoxic and cytotoxic effects, as well as conditions such as obesity, diabetes, cardiovascular disease, and reproductive abnormalities, often associated with their estrogenic action. Microalgae have shown promise in the detoxification of both inorganic and organic contaminants, and several large-scale microalgal systems for wastewater treatment have been developed. However, the progress of algal bioremediation can be influenced by accidental contaminations and operational challenges encountered in pilot-scale research. Microalgae employ various processes, such as bioadsorption, biouptake, and biodegradation, to effectively remediate EPs. During microalgal biodegradation, complex chemical compounds are transformed into simpler substances through catalytic metabolic degradation. Integrating algal bioremediation with existing treatment methodologies offers a viable approach for efficiently eliminating EPs from wastewater. This review focuses on the use of algal-based biological remediation processes for wastewater treatment, the environmental impacts of EPs, and the challenges associated with implementing algal bioremediation systems to effectively remove emerging pollutants.


Assuntos
Poluentes Ambientais , Microalgas , Poluentes Químicos da Água , Humanos , Poluentes Ambientais/metabolismo , Águas Residuárias , Ecossistema , Água/metabolismo , Poluentes Químicos da Água/química , Biodegradação Ambiental , Microalgas/metabolismo
3.
Curr Microbiol ; 78(4): 1245-1255, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33629120

RESUMO

From acid corroded iron plates five different types of actinobacteria were isolated. Among the five, JMCACA3 strain was selected for the present study. In ISP media, JMCACA3 strain showed well-developed aerial and substrate mycelia were observed. This strain showed good growth in 12 different carbon and 4 different nitrogen sources. The 16S rRNA sequence of phylogenetic analysis by neighbor-joining method identified the studied strain belongs to Streptomyces sp. The biodegradation activity of the strain analyzed by UV and FTIR analysis, which revealed that the various concentrations of Benzimidazole inhibitor with JMCACA3 culture showed slightly varied results. For weight loss method, mild steel coupons incubated with JMCACA3 culture, Benzimidazole inhibitor + JMCACA3 culture and mixed sample showed that JMCACA3 strain utilized the inhibitor as their energy source and the weight the coupons were slightly varied, evidenced by XRD spectra and showed Fe2O3 corrosion products. Our study concluded that the JMCACA3 strain, an iron-reducing actinobacteria which utilizes and converted the corrosion inhibitor Benzimidazole as their energy source. So, it is very urgent to develop more powerful corrosion inhibitor from green biocide or microbial-based biocide and their analog which incorporated into the pre-existing Benzimidazole to increase the corrosion inhibitor level against the biofilm of actinobacterial influenced corrosion.


Assuntos
Ferro , Streptomyces , Biofilmes , Corrosão , Filogenia , RNA Ribossômico 16S/genética , Streptomyces/genética
4.
Microb Pathog ; 143: 104138, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32173495

RESUMO

Mushrooms have an important role in sustainability since they have long been used as valuable food source and traditional medicine around the world. Regrettably, they are among the most rigorously affected populations, along with several plants and animals, due to the destructive activities of mankind. Thus the authentication and conservation of mushroom species are constantly needed to exploit the remarkable potential in them. In this perspective, an attempt has been made to identify and assess the biological attributes of psychedelic mushrooms collected from Kodaikanal, Tamil Nadu, India. The macromorphological features of the psychedelic mushroom DPT1 helped its presumptive identification and the molecular characters depicted by DNA marker revealed its close relationship with the genus Psilocybe. Accordingly, the psychedelic mushroom was identified as Psilocybe cubensis DPT1 and its crude ethyl acetate extract on analysis revealed the occurrence of phytoconstituents like alkaloids, flavonoids, tannins, saponins and carbohydrates. Moreover, it exhibited 80% larvicidal activity against Culex quinquefasciatus mosquito at 800 ppm concentration and an array of antibacterial effects with utmost susceptibility of Proteus vulgaris, and the identification of bioactive compounds by different analytical techniques substantiate that the bioactivities might be due to the presence of phytochemicals. The results of the study indicated that the extract of P. cubensis DPT1 having notable antibacterial and mosquito larvicidal efficacies which could be probed further for the isolation of medicinally important as well as bio-control compounds.


Assuntos
Antibacterianos/farmacologia , Culex , Inseticidas/farmacologia , Psilocybe/química , Animais , DNA Fúngico/genética , Cromatografia Gasosa-Espectrometria de Massas , Larva , Testes de Sensibilidade Microbiana , Filogenia , Proteus vulgaris/efeitos dos fármacos , Psilocybe/genética , RNA Ribossômico 18S/genética , Análise de Sequência de DNA
5.
Microb Pathog ; 136: 103713, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31491553

RESUMO

Forty-five bacterial isolates recovered from surface-sterilized root, stem and leaf tissues of tomato were studied for their antifungal activity against phytopathogens, and plant growth-promoting (PGP) and biocontrol traits. Six plant-associated bacteria suppressed all the pathogens tested under in vitro plate assay and also shown PGP and biocontrol traits. The six isolates showing PGP and biocontrol properties were identified as Bacillus spp., based on the microbial identification system (Biolog) and partial sequence analysis of 16S rDNA. Two independent field trials were conducted with biocontrol bacteria along with chemical control (Thiram+Fytolan) and control (Without treatment). The averaged results of two field trails revealed that tomato plants inoculated with BETS11 (11.73 t/ha) and BETR11 (11.24 t/ha) strains showed significantly higher yield and disease reduction on par with chemical control (11.81 t/ha). However, there was an increase in the yield with respect to uninoculated control except the isolate BETS5 (9.09 t/ha). Therefore, the isolates BETS11 and BETR11 may be used as efficient biofertilizer and bio-control agent for tomato production in the Island agricultural ecosystem.


Assuntos
Antifúngicos/metabolismo , Bactérias/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Solanum lycopersicum/crescimento & desenvolvimento , Solanum lycopersicum/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Análise por Conglomerados , DNA Ribossômico/química , DNA Ribossômico/genética , Controle Biológico de Vetores , Filogenia , Doenças das Plantas/prevenção & controle , Folhas de Planta/microbiologia , Raízes de Plantas/microbiologia , Caules de Planta/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
6.
Microb Pathog ; 114: 107-115, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29191704

RESUMO

Pseudomonas aeruginosa is a Gram negative, opportunistic biofilm forming pathogenic bacterium which is developing as a serious problem worldwide. The pathogenicity of P. aeruginosa mainly depends upon biofilm and quorum sensing (QS) mechanism. Targeting biofilm and QS regulated factor will automatically reduce the pathogenicity of P. aeruginosa. Therefore it is compulsory to identify naturally derived biofilm and QS inhibitors against P. aeruginosa. In the present study Oscillatoria subuliformis, a marine cyanobacterium was used against the biofilm and QS of P. aeruginosa. O. subuliformis intracellular methanolic extract (OME) at different concentration (1.5 µg mL-1, 3 µg mL-1 and 5 µg mL-1) was tested against several virulence factors like Extracellular Polymeric Substance (EPS), Cell Surface Hydrophobicity (CSH), elastase, pyocyanin and swarming motility. OME inhibited biofilm (56%), EPS (40%), CSH (56%), pyocyanin (27%), elastase activity and swarming motility in P. aeruginosa without interfering in their survival. Characterization of the OME using FTIR and GCMS confirmed palmitic acid and oleic acid as active compound. CLSM analysis of catheter coated with OME, palmitic and oleic acid proved biofilm inhibition over urinary catheters. The results postulates that oleic and palmitic acid could be an effective attenuator of P. aeruginosa pathogenesis.


Assuntos
Antibacterianos/farmacologia , Infecção Hospitalar/microbiologia , Cianobactérias/química , Oscillatoria/química , Pseudomonas aeruginosa/efeitos dos fármacos , Aderência Bacteriana/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Biofilmes/efeitos dos fármacos , Humanos , Interações Hidrofóbicas e Hidrofílicas , Metaloendopeptidases/metabolismo , Ácido Oleico/farmacologia , Ácido Palmítico/farmacologia , Elastase Pancreática , Pseudomonas aeruginosa/patogenicidade , Piocianina , Percepção de Quorum/efeitos dos fármacos , Virulência/efeitos dos fármacos , Fatores de Virulência/metabolismo
7.
Microb Pathog ; 116: 246-256, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29409746

RESUMO

Biofilm forming pathogenic bacteria showing resistance towards antimicrobial agents has increased the urge to find an alternative treatment strategy. Among the biofilm forming pathogenic bacteria, Pseudomonas aeruginosa is a well-recognised Gram negative biofilm former causing nosocomial infection and other disease among immunocompromised patients. The aim of the current study is to evaluate the antipathogenic potentials of S. platensis against P. aeruginosa. S. platensis methanolic extract (SME) inhibited the biofilm (89%), extracellular polymeric substances (EPS), cell surface hydrophobicity (CSH) (44%), pyocyanin, pyoveridin and swarming motility of P. aeruginosa. Partial purification of SME using thin layer chromatography (TLC), column chromatography and gas chromatography mass spectroscopy (GCMS) revealed the major component as hexadecanoic acid (HxD). Further analysis through in silico approach showed the efficient binding of HxD with the biofilm regulatory proteins (Las R and salidase enzyme) of P. aeruginosa. The coating of HxD over different material surfaces efficiently prevented the adhesion of P. aeruginosa biofilm. The results of the toxicity assay revealed that the SME is non-toxic towards Artemia salina at the given concentration. Hence the overall work proves the potential non-toxic effects of SME against P. aeruginosa pathogenicity.


Assuntos
Antibacterianos/farmacologia , Misturas Complexas/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/crescimento & desenvolvimento , Percepção de Quorum/efeitos dos fármacos , Spirulina/química , Animais , Antibacterianos/isolamento & purificação , Antibacterianos/toxicidade , Artemia/efeitos dos fármacos , Cromatografia Líquida , Cromatografia em Camada Fina , Misturas Complexas/isolamento & purificação , Misturas Complexas/toxicidade , Cromatografia Gasosa-Espectrometria de Massas , Ácido Palmítico/isolamento & purificação , Ácido Palmítico/farmacologia , Ácido Palmítico/toxicidade
8.
Microb Pathog ; 107: 88-97, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28330748

RESUMO

Zinc oxide nanoparticles were synthesized using the aqueous leaf extracts of Plectranthus barbatus (Plb-ZnO NPs) and characterized by UV-visible spectroscopy, XRD, FTIR, SEM and EDS. UV-Visible spectra recorded the absorbance peak of Plb-ZnO NPs at 343 nm. SEM analyses showed the spherical shape of Plb-ZnO NPs with the particle size between 30 and 60 nm. Plb-ZnO NPs exhibited antibacterial and antibiofilm activity against Gram positive Bacillus subtilis at all tested concentrations. In contrast, Plb-ZnO NPs showed antibacterial and antibiofilm activity against Gram negative Vibrio parahaemolyticus and Proteus vulgaris only at 100 µg/ml. The Atomic absorption spectrometry (AAS) revealed that Zn2+ dissolution was 1.87 and 8.8 µg/L at 10 and 160 µg/L of Plb-ZnO NPs respectively. The body accumulation of Zn2+ was increased from 0.8 µg/g body weight to 3.5 µg/g body weight when C. cornuta exposed to 10 µg/L and 160 µg/L respectively. Plb-ZnO NPs were toxic to Ceriodaphnia cornuta neonates (LC50: 28 µg/L). Plb-ZnO NPs caused 100% mortality of C. cornuta at 160 µg/L after 24 h. However, zinc acetate does not cause any mortality of C. cornuta upto 350 µg/L. The light and confocal laser scanning microscopic images evidenced the uptake and accumulation of Plb-ZnO NPs on the internal gut regions of C. cornuta at 160 µg/L after 5, 10, 15, 20 and 24 h. Abnormalities in the swimming behaviour such as erratic swimming (ERR), migration to bottom (BOT) and migration to water surface (SUR) of C. cornuta were noticed after treatment with different concentrations of Plb-ZnO NPs.


Assuntos
Antibacterianos/farmacologia , Artrópodes/microbiologia , Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Nanopartículas/química , Óxido de Zinco/farmacologia , Animais , Antibacterianos/química , Biofilmes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Microscopia Confocal , Microscopia Eletrônica de Varredura , Modelos Animais , Tamanho da Partícula , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Plectranthus/química , Espectrometria por Raios X , Óxido de Zinco/administração & dosagem , Óxido de Zinco/química
9.
Microb Pathog ; 113: 68-73, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29056495

RESUMO

Algae could offer a potential source of fine chemicals, pharmaceuticals and biofuels. In this study, a green synthesis of dispersed cuboidal gold nanoparticles (AuNPs) was achieved using red algae, Gelidium amansii reacted with HAuCl4. It was found to be 4-7 nm sized cubical nanoparticles with aspect ratio of 1.4 were synthesized using 0.5 mM of HAuCl4 by HRSEM analysis. The crystalline planes (111), (200), (220), (311) and elemental signal of gold was observed by XRD and EDS respectively. The major constitutes, galactose and 3,6-anhydrogalactose in the alga played a critical role in the synthesis of crystalline AuNPs with cubical dimension. Further, the antibacterial potential of synthesized AuNPs was tested against human pathogens, Escherichia coli and Staphylococcus aureus. The synthesized AuNPs found biocompatible up to 100 ppm and high concentration showed an inhibition against cancer cell. This novel report could be helped to exploration of bioresources to material synthesis for the application of biosensor and biomedical application.


Assuntos
Antibacterianos/farmacologia , Cloretos/química , Cloretos/farmacologia , Escherichia coli/efeitos dos fármacos , Compostos de Ouro/química , Compostos de Ouro/farmacologia , Nanopartículas Metálicas/química , Rodófitas/metabolismo , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/química , Galactose/análogos & derivados , Galactose/metabolismo , Ouro/química , Humanos
10.
Biofouling ; 31(7): 565-74, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26299260

RESUMO

Candida albicans, an opportunistic pathogen, has been known to form hypoxic biofilms on medical devices which in turn confers resistance towards antifungals, resulting in subsequent therapeutic failures. Inclusion of anti-biofilm agents in the control of infections is a topic of current interest in developing potential anti-infectives. The in vitro anti-fungal and anti-biofilm efficacy of 2,4-di-tert-butyl phenol [DTBP] was evaluated in this study, which revealed the potential fungicidal action of DTBP at higher concentrations where fluconazole failed to act completely. DTBP also inhibited the production of hemolysins, phospholipases and secreted aspartyl proteinase which are the crucial virulence factors required for the invasion of C. albicans. Various anti-biofilm assays and morphological observations revealed the efficacy of DTBP in both inhibiting and disrupting biofilms of C. albicans. Inhibition of hyphal development, a key process that aids in initial adhesion of C. albicans, was observed, and this could be a mechanism for the anti-biofilm activity of DTBP.


Assuntos
Biofilmes , Candida albicans , Fluconazol/farmacologia , Fenóis/farmacologia , Antifúngicos/farmacologia , Antioxidantes/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/fisiologia , Pesquisa Comparativa da Efetividade , Hifas/efeitos dos fármacos , Hifas/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana
11.
Biofouling ; 31(4): 379-91, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26057498

RESUMO

Pseudomonas aeruginosa, an opportunistic pathogen frequently associated with nosocomial infections, is emerging as a serious threat due to its resistance to broad spectrum antimicrobials. The biofilm mode of growth confers resistance to antibiotics and novel anti-biofilm agents are urgently needed. Nanoparticle based treatments and therapies have been of recent interest because of their versatile applications. This study investigates the anti-biofilm activity of copper nanoparticles (CuNPs) synthesized by the one pot method against P. aeruginosa. Standard physical techniques including UV-visible and Fourier transform infrared spectroscopy, X-ray diffraction and transmission electron microscopy were used to characterize the synthesized CuNPs. CuNP treatments at 100 ng ml(-1) resulted in a 94, 89 and 92% reduction in biofilm, cell surface hydrophobicity and exopolysaccharides respectively, without bactericidal activity. Evidence of biofilm inhibition was also seen with light and confocal microscope analysis. This study highlights the anti-biofilm potential of CuNPs, which could be utilized as coating agents on surgical devices and medical implants to manage biofilm associated infections.


Assuntos
Biofilmes/efeitos dos fármacos , Cobre/química , Nanopartículas/química , Pseudomonas aeruginosa/fisiologia , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Incrustação Biológica/prevenção & controle , Farmacorresistência Bacteriana , Microscopia Eletrônica de Transmissão , Extratos Vegetais , Pseudomonas aeruginosa/efeitos dos fármacos
12.
Saudi Pharm J ; 23(4): 421-8, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27134545

RESUMO

Aim is to assess the anti-biofilm property of tenorite nanoparticles and to study their suitability as a possible coating material for medical implants. Tenorite (CuO) nanoparticles were synthesized by the optimized thermal decomposition method and characterized using TEM, XRD, FTIR and UV-Vis analysis. Their influence on biofilm formation of microbes was studied by growing multi drug resistant bacterial strains in the presence or absence of these nanoparticles at various concentrations. The cytotoxicity of nanoparticles on mammalian cells was studied at the corresponding concentrations. The nanoparticles were found to be uniformly dispersed, spherical shaped and <50 nm in size. They showed various degrees of anti-biofilm property against clinically isolated, biofilm forming multi drug resistant microorganisms such as Staphylococcus aureus, Pseudomonas fluorescens, Burkholderia mallei, Klebsiella pneumoniae, and Escherichia coli. Furthermore, Hep-2 cells showed excellent viability at tenorite nanoparticles concentration toxic to microbial growth. These results indicate that tenorite nanoparticles may be ideal candidates for being utilized as coating on medical implants in general and dental implants in particular.

13.
Int J Pharm ; 655: 124052, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38552751

RESUMO

Antimicrobial peptides (AMPs) are promising novel agents for targeting a wide range of pathogens. In this study, microalgal peptides derived from native microalgae were incorporated into polycaprolactone (PCL) with ƙ-Carrageenan (ƙ-C) forming nanofibers using the electrospinning method. The peptides incorporated in the nanofibers were characterized by fourier infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy (SEM), and contact angle measurement. The results showed that peptides with molecular weights < 10 kDa, when loaded into nanofibers, exhibited lower wettability. The SEM analysis revealed a thin, smooth, interconnected bead-like structures. The antimicrobial activity of the electrospun nanofibers was evaluated through disc diffusion, and minimum inhibitory activity against Escherichia coli (MTTC 443), and Staphylococcus aureus (MTTC 96), resulting in zones of inhibition of 24 ± 0.5 mm and 14 ± 0.5 mm, respectively. The in vitro biocompatibility of the synthesized nanofibers was confirmed using in HEK 293 cell lines with an increased cell viability. Interestingly, the fibers also exhibited a significant wound-healing properties when used in vitro scratch assays. In conclusion, algal peptides incorporated with PCL/ ƙ-C were found to exhibit antimicrobial and biocompatible biomaterials for wound healing applications.


Assuntos
Anti-Infecciosos , Microalgas , Nanofibras , Humanos , Carragenina , Nanofibras/química , Células HEK293 , Antibacterianos/farmacologia , Poliésteres/química , Cicatrização , Anti-Infecciosos/farmacologia , Peptídeos/farmacologia
14.
Bull Environ Contam Toxicol ; 90(6): 730-5, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23532276

RESUMO

This investigation examined the efficiency of Dolichospermum flos-aquae NTMS07 in the removal of Cr(VI) from exposure water at various concentrations (2.5, 5, 7.5, 10 mg/L) over different time intervals of contact (1-5 days). Chromium removal was maximum at 2.5 mg/L, and decreased with increased concentration. The responses of the antioxidative enzymes superoxide dismutase (SOD) and catalase (CAT) were measured, and the composition of fatty acids was evaluated at a concentration of 5 mg Cr/L. Significant increases in the activity levels of SOD and CAT were obtained. The level of total unsaturated fatty acids decreased with exposure to Cr. It is proposed that the observed decrease in total unsaturated fatty acid level is a defense mechanism against Cr-induced oxidative stress and cell membrane damage.


Assuntos
Antioxidantes/metabolismo , Catalase/metabolismo , Cromo/toxicidade , Cianobactérias/efeitos dos fármacos , Ácidos Graxos/metabolismo , Água Doce/microbiologia , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Cianobactérias/metabolismo
15.
Biotechnol Lett ; 34(2): 247-51, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22002251

RESUMO

Cr(VI) at 2.5, 5, 7.5 and 10 mg/l was removed over 1-5 days by a freshwater cyanobacterium, Chroococcus sp. 2.5 mg Cr(VI)/l gave the optimum rate. With 5 mg Cr(VI)/l, activities of superoxide dismutase and catalase were increased. Amounts of palmitic (16:0), stearic (18:0) and oleic acid (18:1) in the cell also increased after exposure to Cr(VI).


Assuntos
Cromo/toxicidade , Cianobactérias/efeitos dos fármacos , Ácidos Graxos/metabolismo , Água Doce/microbiologia , Estresse Oxidativo , Catalase/metabolismo , Cianobactérias/enzimologia , Cianobactérias/metabolismo , Superóxido Dismutase/metabolismo
16.
Chemosphere ; 306: 135624, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35810861

RESUMO

Phthalate esters (PEs) one of the widely used plasticizers, and are known for their environmental contamination and endocrine disruption. Hence, it is important to study their distribution in a riverine environment. This study was aimed to determine the Spatio-temporal trends of 16 PEs in surface water, sediment and fish from rivers in southern India, and to assess their environmental health risks. Phthalates were quantified in all matrices with the mean concentrations (∑16PEs) in water, sediment and fish as 35.6 µg/L, 1.25 µg/kg and 17.0 µg/kg, respectively. The Kaveri River is highly loaded with PEs compared to the Thamiraparani and Vellar Rivers. PEs such as DBP, DEHP, DCHP and DiBP were most frequently detected in all matrices, and at elevated concentrations in the dry season. The risk quotient (RQ < 1) suggests that the health risk of PEs from river water and fish to humans is negligible. However, DBP and DEHP from the Kaveri River pose some risk to aquatic organisms (HQ > 1). DEHP from the Vellar River may pose risks to algae and crustaceans. Non-priority phthalate (DiBP) may pose risks to Kaveri and Vellar River fish. The bioaccumulation factor of DCHP and DEHP was found to be very high in Sardinella longiceps and in Centropristis striata, and also exceeded the threshold limit of 5000 suggesting that PEs in the riverine environment may pose some health concerns. This is the first study to assess the spatio-temporal distribution, riverine flux and potential ecological effects of 16 PEs from the southern Indian Rivers.


Assuntos
Dietilexilftalato , Ácidos Ftálicos , Poluentes Químicos da Água , Animais , China , Ésteres , Peixes , Humanos , Medição de Risco , Água , Poluentes Químicos da Água/análise
17.
Bull Environ Contam Toxicol ; 87(3): 254-9, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21720797

RESUMO

Pb(2+) removal ability of the immobilized and free filaments of marine cyanobacteria Oscillatoria sp. NTMS01 and Phormidium sp. NTMS02 was studied using batch experiments. Biosorption of lead by immobilized filaments was studied as a function of pH (2, 4, 6, 8, 10), contact time (5-180 min) and initial lead concentration (1, 3, 5, 7 mg/L) and the removal efficiency of free filaments was studied by culturing in the marine medium with the initial concentration (1, 3, 5, 7 mg/L) at pH 7 and incubated for 10 days. The maximum percentage removal was observed at 25 min for immobilized Oscillatoria sp. NTMS01 and 30 min for immobilized Phormidium sp. NTMS02. At 4th and 6th day of incubation, 89% and 77% removal was observed at 1 mg/L of initial lead concentration by free filaments of Oscillatoria sp. NTMS01 and Phormidium sp. NTMS02 respectively and further the removal was decreased with increasing concentration. Chlorophyll-a content was decreased in a dose dependent manner. About 40 and 50% reduction of chlorophyll-a was observed at higher concentration in Oscillatoria sp. NTMS01 and Phormidium sp. NTMS02 respectively. The adsorption capacity of immobilized Oscillatoria sp. NTMS01 was found to be (Q(max)) 217.39 which is comparatively higher than other sorbents. The Pb(2+) removal efficiency was performed as described in terms of Langmuir and Freundlich isotherms. These organisms is found to fit better by the Langmuir isotherms.


Assuntos
Cianobactérias/metabolismo , Chumbo/isolamento & purificação , Oscillatoria/metabolismo , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Adsorção , Cátions Bivalentes , Concentração de Íons de Hidrogênio , Cinética , Termodinâmica
18.
Microbiol Res ; 245: 126707, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33503538

RESUMO

The environmental noxious e-waste was collected and physicochemical characterized by Scanning electron microscopy (SEM) along with energy dispersive X-ray spectroscopy (EDX), Atomic absorption spectrometry (AAS), and X-ray diffraction analysis (XRD) exploration to understand the presence of toxic metals like Hg, Cd, Pd, Si, Ru. Therefore, the finding provides vital knowledge about the impact of toxic metals from e-waste printed circuit boards as contaminants in the environment and its impact on humans. The Frankia sp. DDNSF-03 and Frankia casuarinae DDNSF-04 were isolated and identified, further utilized for removal of e-waste toxic metals by one and two steps bioremediation experiments executed with various e-waste concentrations. The two-step bioremediation experiment is efficient in the expression of toxic metals that were removed at a lesser concentration of e-waste. Consequently, the presence of organic acids in the Frankia primary metabolites was confirmed by FT-IR analysis besides decreasing the pH level in the Frankia growth medium. The positive control Frankia and negative control e-waste were maintained throughout the bioremediation experiments. The initial Hg 4.3, Cd 8.3, Pd 4.6 (ppm) in the e-waste and final treated with Frankia sp. DDNSF-03 Hg 0.09, Cd 5.09, Pb 0.49 (ppm), and Frankia casuarinae DDNSF-04 Hg 2.15, Cd 5.6, Pb 2.82 (ppm) concentration of toxic metals was quantified by AAS spectrum analysis. The toxic metals mercury and lead were significantly mineralized by Frankia sp. when compare the Frankia casuarinae. The above finding was confirmed the manifestation of morphological changes by an accumulation of e-waste in Frankia hyphae using SEM analysis and obtain the qualitative of toxic metals parallel peaks in EDX analysis.


Assuntos
Biodegradação Ambiental , Resíduo Eletrônico/análise , Frankia/metabolismo , Metais Pesados/metabolismo , Frankia/isolamento & purificação , Humanos , Microbiologia do Solo
19.
Chemosphere ; 279: 130673, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34134428

RESUMO

The pulsed magnetic field (PMF) was adopted for the enhancement of lipid in Chlorella vulgaris. The average biomass and lipid content in outdoor conditions were found to be 0.315 g.L-1 and 20-25% respectively. The effect of magnetic flux density in the range of 600-900 mG on biomass production and lipid content was studied. A magnetic flux density of 700 mG at 1Hz for 4 h per day was found to be optimum, which yielded a maximum dry cell weight of 0.61 g.L-1, two-fold than the normal condition, with a lipid content of 55.2%. FTIR analysis evidenced that the PMF treatment increased the active oxygen, which could be attributed to the enhancement of growth and lipid of C. vulgaris.


Assuntos
Chlorella vulgaris , Microalgas , Biocombustíveis , Biomassa , Lipídeos , Campos Magnéticos
20.
Bioresour Technol ; 339: 125524, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34303097

RESUMO

This present study has attempted to screen four microalgal strainsChlorella vulgaris, Coelastrellasp.Scenedesmus dimorphusandChlorococcumsp. and consortium for biodiesel application.Coelastrella sp. was found to show marginally higher optical density of 1.13 on 19th day whereas C. vulgaris and S. dimorphus consortium showed 1.59 OD. Regarding the dry cell weight, S. dimorphus and Chlorella vulgaris was found to yield higher DCW at about 0.544 and 0.508 g/L, respectively. In outdoor pond raceway pond, C. vulgaris and S. dimorphus yielded 0.76-0.80 g/L while consortium showed 0.87 g/L biomass. In the case of lipid content, S. dimorphus, C. vulgaris and consortium accumulated 36.4, 35.5 and 39.2% lipids, respectively in lab, whereas in outdoor raceway pond it was 26.4, 32.3 and 34.5%, respectively. The fatty profile of Chlorella and Scenedesmus sp. showed linolelaidic acid, and cis-8,11,14-eicosatrienoic acid as prevalent fatty acids whereas the consortium has 53.5% oleic acid than other fatty acids.


Assuntos
Chlorella vulgaris , Microalgas , Biocombustíveis , Biomassa , Ácidos Graxos , Ácido Oleico
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