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1.
Environ Res ; 212(Pt D): 113543, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35613631

RESUMO

Nanotechnology has a wide range of agricultural applications, with emphasize on the development of novel nano-agrochemicals such as, nano-fertilizer and nano-pesticides. It has a significant impact on sustainable agriculture by increasing agricultural productivity, while reducing the use of inorganic fertilizers, pesticides, and herbicides. Nano-coating delivery methods for agrochemicals have improved agrochemical effectiveness, safety, and consistency. Biosynthesis of nanoparticles (NPs) has recently been recognized as an effective tool, contrary to chemically derived NPs, for plant abiotic and biotic stress control, and crop improvement. In this regard, fungi have tremendous scope and importance for producing biogenic NPs of various sizes, shapes, and characteristics. Fungi are potential candidates for synthesis of biogenic NPs due to their enhanced bioavailability, biological activity, and higher metal tolerance. However, their biomimetic properties and high capacity for dispersion in soil, water environments, and foods may have negative environmental consequences. Furthermore, their bioaccumulation raises significant concerns about the novel properties of nanomaterials potentially causing adverse biological effects, including toxicity. This review provides a concise outline of the growing role of fungal-mediated metal NPs synthesis, its potential applications in crop field, and associated issues of nano-pollution in soil and its future implications.


Assuntos
Nanopartículas Metálicas , Nanopartículas , Praguicidas , Agricultura/métodos , Fertilizantes/análise , Fungos , Nanopartículas/química , Nanopartículas/toxicidade , Nanotecnologia/métodos , Solo
2.
Exp Dermatol ; 28(5): 601-608, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30908723

RESUMO

Dermatophytic infections caused by Trichophyton rubrum are the most prevalent superficial mycoses worldwide. The present study was aimed at evaluating the anti-dermatophytic effect of a rhamnolipid biosurfactant (RL) produced by Pseudomonas aeruginosa SS14 (GenBank Accession no. KC866140) against T. rubrum in experimentally induced dermatophytosis in mice models. The purified RL could effectively suppress spore germination and hyphal proliferation of T. rubrum at 500 µg/mL. Ultramicroscopic observations involving SEM and AFM studies revealed severely altered hyphal morphology in the RL-treated mycelia. The membrane disruptive effect of RL was measured by the uptake of propidium iodide (PI) as visualized by CLSM. The absorbance of the RL-treated cell suspension at 260 nm showed concentration-dependant exudation of nucleic acid due to loss of cell membrane integrity. On evaluation of the therapeutic efficacy of RL on experimentally induced cutaneous dermatophytosis in mice models, we observed that the RL, when applied topically at a concentration of 500 µg/mL, was effective in completely curing dermatophytosis at the end of 21-day treatment period. The results were statistically similar to those obtained using the standard drug terbinafine as control. Apart from macroscopic observation, the results were confirmed by culture of skin scrapings and histopathological examination. The results are suggestive of the effectiveness of RL in control of dermatophytosis caused by T. rubrum.


Assuntos
Antifúngicos/farmacologia , Dermatomicoses/tratamento farmacológico , Tensoativos/farmacologia , Tinha/tratamento farmacológico , Trichophyton/efeitos dos fármacos , Animais , Proliferação de Células , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Testes de Sensibilidade Microbiana , Propídio/farmacologia , Pseudomonas aeruginosa/química , Resultado do Tratamento
3.
Microb Cell Fact ; 16(1): 95, 2017 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-28558761

RESUMO

BACKGROUND: Sophorolipids are one of the most promising glycolipid biosurfactants and have been successfully employed in bioremediation and various other industrial sectors. They have also been described to exhibit antimicrobial activity against different bacterial species. Nevertheless, previous literature pertaining to the antifungal activity of sophorolipids are limited indicating the need for further research to explore novel strains with wide antimicrobial activity. A novel yeast strain, Rhodotorula babjevae YS3, was recently isolated from an agricultural field in Assam, Northeast India. This study was primarily emphasized at the characterization and subsequent evaluation of antifungal activity of the sophorolipid biosurfactant produced by R. babjevae YS3. RESULTS: The growth kinetics and biosurfactant production by R. babjevae YS3 was evaluated by cultivation in Bushnell-Haas medium containing glucose (10% w/v) as the sole carbon source. A reduction in the surface tension of the culture medium from 70 to 32.6 mN/m was observed after 24 h. The yield of crude biosurfactant was recorded to be 19.0 g/l which might further increase after optimization of the growth parameters. The biosurfactant was characterized to be a heterogeneous sophorolipid (SL) with both lactonic and acidic forms after TLC, FTIR and LC-MS analyses. The SL exhibited excellent oil spreading and emulsifying activity against crude oil at 38.46 mm2 and 100% respectively. The CMC was observed to be 130 mg/l. The stability of the SL was evaluated over a wide range of pH (2-10), salinity (2-10% NaCl) and temperature (at 120 °C for time intervals of 30 up to 120 min). The SL was found to retain surface-active properties under the extreme conditions. Additionally, the SL exhibited promising antifungal activity against a considerably broad group of pathogenic fungi viz. Colletotrichum gloeosporioides, Fusarium verticilliodes, Fusarium oxysporum f. sp. pisi, Corynespora cassiicola, and Trichophyton rubrum. CONCLUSIONS: The study reports, for the first time, the biosurfactant producing ability of R. babjevae, a relatively lesser studied yeast. The persistent surface active properties of the sophorolipid in extreme conditions advocates its applicability in diverse environmental and industrial sectors. Further, antifungal activities against plant and human pathogens opens up possibilities for development of efficient and eco-friendly antifungal agents with agricultural and biomedical applications.


Assuntos
Antifúngicos/farmacologia , Rhodotorula/química , Tensoativos/farmacologia , Antifúngicos/química , Antifúngicos/metabolismo , Ascomicetos/efeitos dos fármacos , Biomassa , Colletotrichum/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Filogenia , Rhodotorula/genética , Rhodotorula/metabolismo , Tensoativos/química , Tensoativos/metabolismo , Trichophyton/efeitos dos fármacos
4.
J Basic Microbiol ; 55(11): 1265-74, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26173581

RESUMO

The rhamnolipid biosurfactant (RL-DS9) extracted from the bacterial strain Pseudomonas aeruginosa DS9 was evaluated for its antifungal activity against Colletotrichum falcatum that causes red rot in sugarcane. The surface tension (ST) reduction, biosurfactant production, and antifungal activity of biosurfactant against C. falcatum were investigated by using the medium with different carbon sources and it was found to be maximum in glucose. Moreover, highest reduction of ST and production of biosurfactant was achieved at 4.5% (w/v) concentration of glucose. The efficacy of RL-DS9 was compared with a commercially available rhamnolipid (RL-R95) using microtitre plate assay. Results showed that at 100 µg ml(-1) concentration RL-DS9 exhibited 86.6% inhibition against C. falcatum spore germination, and in the same concentration RL-R95 showed 83.3% inhibition. From liquid chromatography-mass spectrometry (LC-MS) analysis, it was revealed that only two similar congeners Rha-(C10 ) and Rha-Rha-(C10:1 ) were found to be in common among both the rhamnolipids. In the plant bioassay test, it was noted that red rot incidence was reduced on the sugarcane plants treated with RL-DS9. This is the first report that rhamnolipid biosurfactant produced by Pseudomonas aeruginosa DS9 could be able to control red rot disease of sugarcane caused due to the infection with the fungus Colletotrichum falcatum.


Assuntos
Antifúngicos , Colletotrichum/efeitos dos fármacos , Glicolipídeos , Pseudomonas aeruginosa/metabolismo , Antifúngicos/farmacologia , Bioensaio , Glicolipídeos/biossíntese , Glicolipídeos/farmacologia , Saccharum/microbiologia
5.
J Biomol Struct Dyn ; : 1-13, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38321959

RESUMO

Medicinal plants play an important role as antimicrobials by inhibiting various key targets of diverse microorganisms. A major antimicrobial component of plants is its essential oil, which are increasingly being studied for their antimicrobial properties as well as for their potential role in the inhibition of biofilm formation. In the present study, essential oil from Kaempferia galanga L was isolated resulting in the identification of eleven compounds. Of these, two of the compounds, γ-elemene and caryophyllene were found to dock with the target proteins, CrtM and SarA of Staphylococcus aureus, which are essential for the formation of biofilm. γ-elemene demonstrated the best binding affinity with CrtM with binding energy of -8.1 kcal/mol whereas caryophyllene and its derivative isocaryophyllene showed the best binding with SarA with binding energy -6.1 kcal/mol. ADMET study of the compounds also revealed that the compounds are non-toxic and can be used as probable compounds for inhibition of biofilms. Molecular dynamic simulation studies revealed high affinity of binding and stability of the molecules with their targets. PCA analysis helped in identifying the principal motions occurring within a trajectory that are essential in inducing conformational changes.Communicated by Ramaswamy H. Sarma.

6.
Environ Pollut ; 285: 117519, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34380220

RESUMO

A native strain of Bacillus paramycoides isolated from the leachate of coal mine overburden rocks was investigated for its potential to produce selenium nanoparticles (SeNPs) by biogenic reduction of selenite, one of the most toxic forms of selenium. 16S rDNA sequencing was used to identify the bacterial strain (SP3). The SeNPs were characterized using spectroscopic (UV-Vis absorbance, dynamic light scattering, X-ray diffraction, and Raman), surface charge measurement (zeta potential), and ultramicroscopic (FESEM, EDX, FETEM) analyses. SP3 exhibited extremely high selenite tolerance (1000 mM) and reduced 10 mM selenite under 72 h to produce spherical monodisperse SeNPs with an average size of 149.1 ± 29 nm. FTIR analyses indicated exopolysaccharides coating the surface of SeNPs, which imparted a charge of -29.9 mV (zeta potential). The XRD and Raman spectra revealed the SeNPs to be amorphous. Furthermore, biochemical assays and microscopic studies suggest that selenite was reduced by membrane reductases. This study reports, for the first time, the reduction of selenite and biosynthesis of SeNPs by B. paramycoides, a recently discovered bacterium. The results suggest that B. paramycoides SP3 could be exploited for eco-friendly removal of selenite from contaminated sites with the concomitant biosynthesis of SeNPs.


Assuntos
Nanopartículas , Selênio , Bacillus , Carvão Mineral , Ácido Selenioso
7.
Biotechnol Rep (Amst) ; 27: e00516, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32884912

RESUMO

Dermatophytes are responsible for a majority of fungal infections in humans and other vertebrates, causing dermatophytosis. Treatment failures are often associated with biofilm formation, making dermatophytes resistant to antifungals. In this study, effects of a rhamnolipid (RL-SS14) produced by Pseudomonas aeruginosa SS14 on planktonic cells of Trichophyton rubrum and Trichophyton mentagrophytes, their biofilm formation, and disruption of mature biofilms were assessed. The composition of RL-SS14 was analysed using FTIR, HPLC-ESI-MS, and GC-MS. Minimum inhibitory concentrations against the planktonic forms of T. rubrum and T. mentagrophytes were 0.5 mg/mL and 0.125 mg/mL, respectively. Crystal-violet (biofilm biomass) and safranin (extracellular matrix) staining revealed that RL-SS14 significantly inhibited biofilm formation and also reduced preformed biofilms in a dose-dependent manner. Microscopic visualization of treated biofilms via SEM, AFM, and CLSM revealed marked morphological damage, cell death, and reduced extracellular matrix. The results indicate the potential of RL-SS14 as an anti-biofilm agent against dermatophytes.

8.
Front Microbiol ; 11: 329, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32226417

RESUMO

Trichophyton mentagrophytes, a zoophilic species, is one of the most frequently isolated dermatophytes in many parts of the world. This study investigated the efficacy of a sophorolipid (SL-YS3) produced by Rhodotorula babjevae YS3 against dermatophytosis caused by T. mentagrophytes. SL-YS3 was characterized by gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography, coupled with electrospray mass spectrometry (UPLC-ESI-MS). SL-YS3 comprised of six different fatty acids as the hydrophobic components of constituent congeners and sophorose as the hydrophilic component. Inhibitory effects of purified SL-YS3 against hyphal growth was found to be 85% at a 2 mg ml-1 concentration, and MIC was 1 mg ml-1. Microscopic examination with scanning electron microscopy (SEM), atomic force microscopy, and confocal laser scanning microscopy (CLSM) revealed that SL-YS3 exerts its effect by disrupting cell membrane integrity causing cell death. SL-YS3 was also effective in reducing the biofilms formed by T. mentagrophytes, which was observed spectrophotometrically with crystal-violet staining and further validated with SEM and CLSM studies of treated biofilms. In vivo studies in a mouse model of cutaneous dermatophytosis involving macroscopic observations, percent culture recovery from skin samples, and histopathological studies showed that SL-YS3 could effectively cure the infected mice after 21 days of topical treatment. Terbinafine (TRB) was used as a standard drug in the experiments. We demonstrate, for the first time, the antidermatophytic activity of a sophorolipid biosurfactant. The findings are suggestive that SL-YS3 can be formulated as a novel antifungal compound to treat cutaneous mycoses caused by T. mentagrophytes.

9.
Colloids Surf B Biointerfaces ; 182: 110358, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31325779

RESUMO

In this study, rhamnolipid (RL) production by Pseudomonas aeruginosa SS14 utilizing rice based Distillers Dried Grains with Solubles (rDDGS) as the sole carbon source was evaluated and the production parameters were optimized using response surface methodology. Highest RL (RL-rDDGS) yield was 14.87 g/L in a culture medium containing 12% (w/v) rDDGS and 11% (v/v) inoculum concentration after 48 h of fermentation at 35 °C. RL-rDDGS was produced as a mixture of mono and di-RL congeners with four novel homologues Rha-C18:2, Rha-C19, Rha-C9, and Rha-Rha-C19. The RL reduced the surface tension of water to 34.8 mN/m at a critical micelle concentration (CMC) value of 100 mg/L, exhibited high stability at a wide range of pH (6-12), heating time (0-120 min), and salinity (2-12% NaCl). Furthermore, RL-rDDGS demonstrated appreciable biofilm disruptive property against Candida tropicalis. This is the first report on the usage of rDDGS for sustainable and low cost production of RL.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida tropicalis/efeitos dos fármacos , Glicolipídeos/farmacologia , Oryza/química , Tensoativos/farmacologia , Antifúngicos/economia , Antifúngicos/isolamento & purificação , Antifúngicos/metabolismo , Biofilmes/crescimento & desenvolvimento , Candida tropicalis/crescimento & desenvolvimento , Estabilidade de Medicamentos , Análise Fatorial , Fermentação , Glicolipídeos/biossíntese , Glicolipídeos/economia , Glicolipídeos/isolamento & purificação , Temperatura Alta , Concentração de Íons de Hidrogênio , Micelas , Testes de Sensibilidade Microbiana , Oryza/metabolismo , Pseudomonas aeruginosa , Salinidade , Sementes/química , Sementes/metabolismo , Tensão Superficial , Tensoativos/economia , Tensoativos/isolamento & purificação , Tensoativos/metabolismo , Água/química
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