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1.
Arch Biochem Biophys ; 699: 108764, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33460582

RESUMO

The interaction of a dirhamnolipid biosurfactant secreted by Pseudomonas aeruginosa with calcium ATPase from sarcoplasmic reticulum (SR) was studied by means of different approaches, such as enzyme activity, fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and molecular docking simulations. The ATP hydrolysis activity was fully inhibited by incubation with dirhamnolipid (diRL) up to 0.1 mM concentration, corresponding to a surfactant concentration below membrane solubilization threshold. Surfactant-protein interaction induced conformational changes in the protein observed by an increase in the accessibility of tryptophan residues to the aqueous phase and by changes in the secondary structure of the protein as seen by fluorescence and FTIR spectroscopy. As a consequence, the protein become more unstable and denatured at lower temperatures, as seen by enzyme activity and DSC studies. Finally, these results were explained at molecular level throughout molecular docking simulations. It is concluded that there is a specific dirhamnolipid-protein interaction not related to the surface activity of the surfactant but to the particular physicochemical properties of the biosurfactant molecule.


Assuntos
Glicolipídeos/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Tensoativos/metabolismo , Animais , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Glicolipídeos/química , Simulação de Acoplamento Molecular , Ligação Proteica , Estrutura Secundária de Proteína/efeitos dos fármacos , Pseudomonas aeruginosa/química , Coelhos , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/antagonistas & inibidores , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/química , Tensoativos/química
2.
Ecotoxicol Environ Saf ; 208: 111621, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396141

RESUMO

The study explored the polycyclic aromatic hydrocarbon tolerance of indigenous biosurfactant producing microorganisms. Three bacterial species were isolated from crude oil contaminated sites of Haldia, West Bengal. The three species were screened for biosurfactant production and identified by 16S rRNA sequencing as Brevundimonas sp. IITISM 11, Pseudomonas sp. IITISM 19 and Pseudomonas sp. IITISM 24. The strains showed emulsification activities of 51%, 57% and 63%, respectively. The purified biosurfactants were characterised using FT-IR, GC-MS and NMR spectroscopy and found to have structural similarities to glycolipopeptides, cyclic lipopeptides and glycolipids. The biosurfactants produced were found to be stable under a wide range of temperature (0-100 °C), pH (4-12) and salinity (up to 20% NaCl). Moreover, the strains displayed tolerance to high concentrations (275 mg/L) of anthracene and fluorene and showed a good amount of cell surface hydrophobicity with different hydrocarbons. The study reports the production and characterisation of biosurfactant by Brevundimonas sp. for the first time. Additionally, the kinetic parameters of the bacterial strains grown on up to 300 mg/L concentration of anthracene and fluorene, ranged between 0.0131 and 0.0156 µmax (h-1), while the Ks(mg/L) ranged between 59.28 and 102.66 for Monod's Model. For Haldane-Andrew's model, µmax (h-1) varied between 0.0168 and 0.0198. The inhibition constant was highest for Pseudomonas sp. IITISM 19 on anthracene and Brevundimonas sp. IITISM 11 on fluorene. The findings of the study suggest that indigenous biosurfactant producing strains have tolerance to high PAH concentrations and can be exploited for bioremediation purposes.


Assuntos
Antracenos/metabolismo , Biodegradação Ambiental , Fluorenos/metabolismo , Tensoativos/metabolismo , Antracenos/química , Bactérias/metabolismo , Fluorenos/química , Glicolipídeos , Hidrocarbonetos/metabolismo , Cinética , Petróleo/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Pseudomonas/metabolismo , RNA Ribossômico 16S/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Tensoativos/química
3.
Ecotoxicol Environ Saf ; 207: 111514, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33254394

RESUMO

The present study investigated the stability and efficacy of a biosurfactant produced by Klebsiella sp. KOD36 under extreme conditions and its potential for enhancing the solubilization and degradation of phenanthrene in various environmental matrices. Klebsiella sp. KOD36 produced a mono-rhamnolipids biosurfactant with a low critical micelle concentration (CMC) value. The biosurfactant was stable under extreme conditions (60 °C, pH 10 and 10% salinity) and could lower surface tension by 30% and maintained an emulsification index of > 40%. The emulsion index was also higher (17-43%) in the presence of petroleum hydrocarbons compared to synthetic surfactant Triton X-100. Investigation on phenanthrene degradation in three different environmental matrices (aqueous, soil-slurry and soil) confirmed that the biosurfactant enhanced the solubilization and biodegradation of phenanthrene in all matrices. The high functional stability and performance of the biosurfactant under extreme conditions on phenanthrene degradation show the great potential of the biosurfactant for remediation applications under harsh environmental conditions.


Assuntos
Biodegradação Ambiental , Klebsiella/fisiologia , Fenantrenos/metabolismo , Tensoativos/metabolismo , Meios de Cultura , Emulsões , Glicolipídeos , Hidrocarbonetos/metabolismo , Klebsiella/metabolismo , Micelas , Petróleo/metabolismo , Solo , Poluentes do Solo/metabolismo
4.
Ecotoxicol Environ Saf ; 207: 111292, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32919193

RESUMO

As a hydrophobic pollutant, benzo(a)pyrene (BaP) is difficult to be degraded by microbes due to its poor water solubility. To improve its water solubility, this study harvested a biosurfactant from swine wastewater. The role of the biosurfactant in BaP biodegradation in contaminated water and soil were investigated. The biodegradation kinetics of BaP in contaminated water and the improvement of soil properties were determined. Results showed that critical micelle concentration (CMC) of the biosurfactant was 46.8 mg/L. The biosurfactant has a high pH stability in range of 3-9 and a strong salt stability in NaCl concentration range of 0-20%. At concentrations of 1, 2, 3, 4 and 5 CMC, the biosurfactant increased BaP water solubility by 1.4, 2.6, 4.0, 5.2 and 6.6 times. BaP biodegradation in contaminated water was effectively promoted by the biosurfactant, and the concentrations of BaP in sludge phase decreased to 1.015 mg/L (47.9% decrement) and 0.675 mg/L (65.4% decrement) when the dosed biosurfactant were 1 and 3 CMC, respectively. The biodegradation kinetics of BaP in contaminated water by the biosurfactant fitted well with the two-compartment kinetic model well (R2 > 0.90). For the bioremediation of BaP contaminated soil, adding 0.1%-0.5% (w/w) biosurfactant biodegraded 39.2%-84.8% of BaP, while the control without biosurfactant was 24.2%. In addition, the application of the biosurfactant significantly improved the properties of the contaminated soil, behaved as the increase in microbial quantity, water holding capacity (WHC) and dehydrogenase (DH) activity of the soil. To sum up, the biosurfactant facilitated the BaP biodegradation and can be effectively used in in-site remediation of polycyclic aromatic hydrocarbons (PAHs) (BaP in this study) contaminated water and soil.


Assuntos
Benzo(a)pireno/análise , Recuperação e Remediação Ambiental/métodos , Poluentes do Solo/análise , Tensoativos/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Animais , Biodegradação Ambiental , Cinética , Pseudomonas/metabolismo , Solo/química , Solubilidade , Tensoativos/metabolismo , Suínos , Águas Residuárias/microbiologia
5.
J Agric Food Chem ; 68(52): 15478-15489, 2020 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-33319980

RESUMO

Rhamnolipid is the main group of biosurfactants predominantly produced by Pseudomonas aeruginosa, a ubiquitous and opportunistic pathogen, which limits its large-scale exploitation. Thus, cost-effective rhamnolipid production from a newly isolated nonpathogenic Enterobacter sp. UJS-RC was investigated. The highest rhamnolipid production (4.4 ± 0.2 g/L) was achieved in a medium constituting agroindustrial wastes (sugarcane molasses and corn steep liquor) as substrates. Rhamnolipid exhibited reduced surface tension to 72-28 mN/m with an emulsification index of 75%. The structural analyses demonstrated the presence of methoxyl, carboxyl, and hydroxyl groups in rhamnolipid. Mass spectra indicated eight rhamnolipid congeners, where dirhamnolipid (m/z 650.01) was the dominant congener. Rhamnolipid inhibited biofilm formation of Staphylococcus aureus in a dose-dependent manner, supported by scanning electron microscopy disclosing the disruption of the microcolony/exopolysaccharide matrix. Rhamnolipid's ability to generate reactive oxygen species has thrown light on the mechanism through which the killing of test bacteria may occur.


Assuntos
Biofilmes/efeitos dos fármacos , Enterobacter/metabolismo , Glicolipídeos/metabolismo , Glicolipídeos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Tensoativos/metabolismo , Agricultura , Biotransformação , Enterobacter/química , Glicolipídeos/química , Melaço/análise , Saccharum/metabolismo , Saccharum/microbiologia , Staphylococcus aureus/fisiologia , Tensoativos/química , Resíduos/análise , Microbiologia da Água , Zea mays/metabolismo , Zea mays/microbiologia
6.
Am J Physiol Lung Cell Mol Physiol ; 319(3): L562-L575, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32579393

RESUMO

The poorly understood tolerance toward high tidal volume (VT) ventilation observed in critically ill children and age-equivalent animal models may be explained by surfactant homeostasis. The aim of our prospective animal study was to test whether high VT with adequate positive end-expiratory pressure (PEEP) is associated with surfactant de novo synthesis and secretion, leading to improved lung function, and whether extreme mechanical ventilation affects intracellular lamellar body formation and exocytosis. Rats (14 days old) were allocated to five groups: nonventilated controls, PEEP 5 cmH2O with VT of 8, 16, and 24 mL/kg, and PEEP 1 cmH2O with VT 24 mL/kg. Following 6 h of ventilation, lung function, surfactant proteins and phospholipids, and lamellar bodies were assessed by forced oscillation technique, quantitative real-time polymerase chain reaction, mass spectrometry, immunohistochemistry, and transmission electron microscopy. High VT (24 mL/kg) with PEEP of 5 cmH2O improved respiratory system mechanics and was not associated with lung injury, elevated surfactant protein expression, or surfactant phospholipid content. Extreme ventilation with VT 24 mL/kg and PEEP 1 cmH2O produced a mild inflammatory response and correlated with higher surfactant phospholipid concentrations in bronchoalveolar lavage fluid without affecting lamellar body count and morphology. Elevated phospholipid concentrations in the potentially most injurious strategy (VT 24 mL/kg, PEEP 1 cmH2O) need further evaluation and might reflect accumulation of biophysically inactive small aggregates. In conclusion, our data confirm the resilience of infant rats toward high VT-induced lung injury and challenge the relevance of surfactant synthesis, storage, and secretion as protective factors.


Assuntos
Lesão Pulmonar/metabolismo , Lesão Pulmonar/fisiopatologia , Surfactantes Pulmonares/metabolismo , Volume de Ventilação Pulmonar/fisiologia , Animais , Líquido da Lavagem Broncoalveolar/citologia , Pulmão/metabolismo , Pulmão/fisiopatologia , Ratos , Mecânica Respiratória/fisiologia , Tensoativos/metabolismo
7.
PLoS Biol ; 18(6): e3000728, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32516311

RESUMO

The development of multicellularity is a key evolutionary transition allowing for differentiation of physiological functions across a cell population that confers survival benefits; among unicellular bacteria, this can lead to complex developmental behaviors and the formation of higher-order community structures. Herein, we demonstrate that in the social δ-proteobacterium Myxococcus xanthus, the secretion of a novel biosurfactant polysaccharide (BPS) is spatially modulated within communities, mediating swarm migration as well as the formation of multicellular swarm biofilms and fruiting bodies. BPS is a type IV pilus (T4P)-inhibited acidic polymer built of randomly acetylated ß-linked tetrasaccharide repeats. Both BPS and exopolysaccharide (EPS) are produced by dedicated Wzx/Wzy-dependent polysaccharide-assembly pathways distinct from that responsible for spore-coat assembly. While EPS is preferentially produced at the lower-density swarm periphery, BPS production is favored in the higher-density swarm interior; this is consistent with the former being known to stimulate T4P retraction needed for community expansion and a function for the latter in promoting initial cell dispersal. Together, these data reveal the central role of secreted polysaccharides in the intricate behaviors coordinating bacterial multicellularity.


Assuntos
Myxococcus xanthus/citologia , Myxococcus xanthus/metabolismo , Polissacarídeos Bacterianos/metabolismo , Acetilação , Vias Biossintéticas/genética , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Membrana Celular/metabolismo , Família Multigênica , Myxococcus xanthus/genética , Polissacarídeos Bacterianos/química , Espectroscopia de Prótons por Ressonância Magnética , Tensoativos/metabolismo
8.
Biofouling ; 36(2): 210-221, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32292058

RESUMO

Surfactin is a type of cyclic lipopeptide biosurfactant implicated in a wide range of applications. Although its antimicrobial activity has been characterized, its effect on Candida albicans physiology remains to be elucidated. The present study evaluated the influence of surfactin-C15 (SF) and its complexes with divalent counterions on C. albicans biofilm formation and preformed biofilms. The SF and metal(II)-SF complexes inhibited biofilm formation and reduced the metabolic activity of mature biofilms in a concentration-dependent manner. The same concentrations of the compounds studied dislodged preexisting biofilms grown on polystyrene plates. Moreover, SF and its metal(II) complexes reduced the mRNA expression of hypha-specific genes HWP1, ALS1, ALS3, ECE1 and SAP4 without exhibiting significant growth inhibition. Further research showed that the compounds tested reduced cellular surface hydrophobicity (CSH). These results suggest that SF and metal(II)-SF complexes could be used as anti-biofilm agents against C. albicans hypha-related infections in clinical practice.


Assuntos
Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Hifas/efeitos dos fármacos , Lipopeptídeos/farmacologia , Peptídeos Cíclicos/farmacologia , Tensoativos/metabolismo , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida albicans/crescimento & desenvolvimento , Candida albicans/metabolismo , Proteínas Fúngicas/genética , Proteínas de Fluorescência Verde/genética , Hifas/crescimento & desenvolvimento
9.
Chemosphere ; 250: 126332, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32234626

RESUMO

Vermiremediation, which uses earthworms to remediate polluted soils, is an expanding technology in recently years. Surfactants have been widely used in bioremediation and other remediation technologies. However, the roles of surfactants in vermiremediation have been rarely studied. In this paper, an investigation of the effects of Tween-80 and rhamnolipid surfactant on the fluoranthene fraction distribution, vermiaccumulation, and removal during vermiremediation was conducted. Both Tween-80 and rhamnolipid improved the proportion of the desorbed fraction, bound residual fluoranthene, and correspondingly, proportions of the non-desorbed fraction were reduced. The vermiaccumulation of fluoranthene was significantly elevated by 35-64.1% and 34.5-44.2% by the Tween-80 and rhamnolipid, respectively. The vermiaccumulation of fluoranthene is positively correlated with the proportion of desorbed fraction of fluoranthene. Moreover, Tween-80 and rhamnolipid enhanced the removal of fluoranthene from contaminated soil during vermiremediation by 43.6-189.2% and 14.7-45.6%, respectively. The enhanced removal of fluoranthene was attributed to stimulated microbial degradation and increased vermiaccumulation resulting from the desorption ability of surfactants and earthworm activity. However, the total amount of fluoranthene that accumulated in earthworms was approximately 4-10% of the initial amount in the treatments, which suggested that microbial degradation rather than direct uptake contributed to the fluoranthene removal. The study suggests that the use of surfactants to enhance the efficiency of vermiremediation of polycyclic aromatic hydrocarbons (PAHs) contaminated soils might be feasible, and that surfactants-enhanced vermiremediation is an alternative strategies for treat PAHs contaminated soils.


Assuntos
Biodegradação Ambiental , Fluorenos/metabolismo , Oligoquetos/metabolismo , Poluentes do Solo/metabolismo , Tensoativos/química , Animais , Glicolipídeos , Hidrocarbonetos Policíclicos Aromáticos/análise , Polissorbatos , Solo , Microbiologia do Solo , Poluentes do Solo/análise , Tensoativos/metabolismo
10.
Microbiol Res ; 236: 126466, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32193126

RESUMO

Since the advent of biologics in human welfare various bio-molecules have been explored. Different bacterial exopolysaccharides have proved their worth in many industrial and commercial applications. In this perspective, while exploring a surfactant exopolysaccharide of Ochrobactrum pseudintermedium C1, it is strikingly observed that it possesses a potent antibacterial property which encourages its bio-medical applications. Following isolation and purification of the said exopolysaccharide, its structural configuration and functional attributes are studied by several analytical procedures involving FTIR, 13C- NMR, CHN-analysis, estimation of zeta potential, XRD-study and digital tensiometry. When treated with pathological samples in vitro, it distinctly elicits its antibacterial property by exhibiting a characteristic zone of inhibition. Combined with a standard antibiotic (like ciprofloxacin), it enhances the action of antibiotic also. Mechanism of its antibacterial action is evaluated by crystal violet entrapment assay with UV-vis spectrophotometry, bacterial cell viability assay by trypan blue staining and SEM study. Results show that its basic surfactant property, anionic character, crystalline nature and scaffolding architecture are supposed to facilitate its antibacterial property which is manifested by its capability of disrupting bacterial cell envelope causing eventual cell death. In the current global scenario, an increasing threat of antibiotic resistance is prevailing due to their indiscriminate use. If used as an adjuvant with a judicious dose of antibiotic, this bio-molecule might play a significant role in bio-medicine to combat such threat.


Assuntos
Antibacterianos/biossíntese , Antibacterianos/farmacologia , Ochrobactrum , Polissacarídeos Bacterianos/biossíntese , Tensoativos/metabolismo , Antibacterianos/metabolismo , Quimioterapia Adjuvante , Ciprofloxacino/farmacologia , Escherichia coli/efeitos dos fármacos , Humanos , Técnicas In Vitro , Testes de Sensibilidade Microbiana , Ochrobactrum/metabolismo , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/metabolismo , Staphylococcus aureus/efeitos dos fármacos
11.
J Phys Chem Lett ; 11(8): 2977-2982, 2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-32202805

RESUMO

Interfacially active lipases can be immobilized at a biphasic interface to enhance turnover recyclability and to facilitate product separation. Extensive coarse-grained molecular dynamics simulations of lipase A (LipA) from Bacillus subtilis show a bimodal orientational distribution of the enzyme at an oil-water interface, arising from its ellipsoidal Janus particle-like character. The relative orientational preference can be tuned by pH. The simulations rationalize a rare experimental observation of an order of magnitude increase in the turnover rate of this lipase upon its noncovalent tagging by a single surfactant molecule at the interface, compared to its rate in bulk water. The adsorption free energy, the interfacial activation, a decrease in the number of orientational fluctuations, and an increased rate of translational diffusion, to all of which the Janus character of LipA contributes, are the factors responsible for this enhancement. This study can spur further investigations of the Janus behavior of enzymes to enhance their activity as well as to stabilize the biphasic emulsion needed for interfacial catalysis.


Assuntos
Óleos/química , Esterol Esterase/química , Tensoativos/química , Água/química , Sítios de Ligação/fisiologia , Óleos/metabolismo , Esterol Esterase/metabolismo , Propriedades de Superfície , Tensoativos/metabolismo , Água/metabolismo
12.
Arch Microbiol ; 202(6): 1407-1417, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32173773

RESUMO

Pseudomonas spp. are the main producers of rhamnolipids. These products have applications in pharmaceuticals, cosmetics, food industry and bioremediation. The biosynthesis of rhamnolipids is influenced by nutrient composition, pH and temperature. In this study, the impact of nutrients on the expression levels of rhamnolipid synthesis genes was evaluated in P. aeruginosa ATCC 15442. Glucose and glycerol were used as carbon sources; while, NaNO3, NH4NO3 and yeast extract/peptone were employed as nitrogen sources. The effect of different concentrations of Fe2+ and Fe3+ on rhamnolipid synthesis genes was also evaluated. Highest biosurfactant production was obtained in minimal medium supplemented with glucose, NaNO3 and Fe2+. Two rhamnolipid synthesis genes, rhlA and rhlB, were amplified with PCR. CapLC ESI-Ion trap-MS/MS detected only mono-rhamnolipid Rha-C10-C10 in the extract. Although similar induction levels were recorded in the presence of 0.05 g/L iron ions, the presence of Fe2+ resulted in higher expression levels than Fe3+ at concentrations equivalent to 0.025 and 0.075 g/L.


Assuntos
Carbono/metabolismo , Glicolipídeos/biossíntese , Ferro/metabolismo , Nitrogênio/metabolismo , Pseudomonas aeruginosa/metabolismo , Glucose/metabolismo , Glicerol/metabolismo , Íons/metabolismo , Nitratos/metabolismo , Peptonas/metabolismo , Pseudomonas aeruginosa/genética , Tensoativos/química , Tensoativos/metabolismo , Espectrometria de Massas em Tandem
13.
Adv Colloid Interface Sci ; 277: 102109, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32028074

RESUMO

Plasticisers are widely used to provide desirable mechanical properties of many polymeric materials. These small molecule additives are also known to leach from the finished products, and this not only may modify the physical properties but the distribution of these materials in the environment and in the human body can cause long-term health concerns and environmental challenges. Many of these plasticisers are esters of polyvalent acids and phthalic acid has previously been predominant but various alternatives are now being more widely explored. The eventual distribution of these compounds depends not just on solubility in aqueous media and on vapour pressure but also on their interaction with other materials, particularly lipids and amphiphiles. This review provides an overview of both the basic physical data (solubility, partition coefficients, surface tension, vapour pressure) that is available in the literature and summarises what has been learnt about the molecular interactions of various plasticisers with surfactants and lipids.


Assuntos
Plastificantes/química , Polímeros/química , Tensoativos/química , Humanos , Plastificantes/metabolismo , Polímeros/metabolismo , Solubilidade , Tensoativos/metabolismo
14.
J Colloid Interface Sci ; 566: 234-241, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32006819

RESUMO

HYPOTHESIS: Lysine based cationic surfactants are well-tolerated tools for hydrophobic ion pairing (HIP) with DNA and its incorporation into lipophilic delivery systems. EXPERIMENTS: Di-Boc-lysine was esterified with 1-hexadecanol and the Boc-residues were cleaved off resulting in hexadecyl lysinate (HL). Subsequently, its Log POctanol/water and the critical micelle concentration (CMC) were determined. Degradability was evaluated utilizing trypsin and pancreas lipase as well as Caco-2 cells. Afterwards, the viability of Caco-2 cells upon incubation with HL was investigated. Finally, HL was ion-paired with plasmid DNA (pDNA, 6159 bp) and the obtained complex was incorporated into self-emulsifying drug delivery systems (SEDDS) for transfection studies on HEK-293 cells. FINDINGS: HL was synthesized with a yield of 53% and subsequent characterization revealed a Log PWater/Octanol of 0.05 and a CMC of 2.7 mM. Enzymatic degradation studies showed rapid degradation of HL by isolated enzymes and Caco-2 cells and cell viability experiments revealed no toxic effect of HL even in a concentration of 250 µg·ml-1 within 24 h. HIP with pDNA was the most efficient in a molar ratio of 6159:1 (HL:pDNA) equalling a charge ratio of 1:1. Formed complexes could be incorporated into SEDDS facilitating successful transfection of HEK-293 cells.


Assuntos
Aminoácidos/metabolismo , DNA/metabolismo , Sistemas de Liberação de Medicamentos , Tensoativos/metabolismo , Aminoácidos/química , Células CACO-2 , DNA/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Estrutura Molecular , Tensoativos/química
15.
Bull Environ Contam Toxicol ; 104(2): 253-258, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31898751

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) and naphthenic acids (NAs) are toxic contaminants of environmental concern found in process water and mature fine tailings, or tailings, from the oil sands industry. BioTiger™, a patented microbial consortium of twelve natural environmental isolates, was found to cometabolically biodegrade the NA hexanoic acid and the PAH phenanthrene in the presence of tailings. Hexanoamide was found to be produced and consumed during cometabolism of hexanoic acid. Mechanistic analysis demonstrated three of the BioTiger™ strains generated biosurfactants with the bacterial adhesion to hydrocarbons assay, seven with the methylene blue active substances assay, and nine with a hemolysis assay. Serial transfers of the BioTiger™ consortium demonstrated the stability of hexanoic acid degradation over several generations. The results demonstrate that BioTiger™ cometabolically biodegrades combinations of phenanthrene and hexanoic acid in tailings. This work reveals the potential for in situ bioremediation of tailings with this natural microbial consortium.


Assuntos
Caproatos/metabolismo , Consórcios Microbianos/fisiologia , Campos de Petróleo e Gás , Fenantrenos/metabolismo , Poluentes do Solo/metabolismo , Bactérias/metabolismo , Aderência Bacteriana , Biodegradação Ambiental , Campos de Petróleo e Gás/microbiologia , Tensoativos/metabolismo
16.
Sci Rep ; 10(1): 1340, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992807

RESUMO

Microorganisms represent the most abundant biomass on the planet; however, because of several cultivation technique limitations, most of this genetic patrimony has been inaccessible. Due to the advent of metagenomic methodologies, such limitations have been overcome. Prevailing over these limitations enabled the genetic pool of non-cultivable microorganisms to be exploited for improvements in the development of biotechnological products. By utilising a metagenomic approach, we identified a new gene related to biosurfactant production and hydrocarbon degradation. Environmental DNA was extracted from soil samples collected on the banks of the Jundiaí River (Natal, Brazil), and a metagenomic library was constructed. Functional screening identified the clone 3C6, which was positive for the biosurfactant protein and revealed an open reading frame (ORF) with high similarity to sequences encoding a hypothetical protein from species of the family Halobacteriaceae. This protein was purified and exhibited biosurfactant activity. Due to these properties, this protein was named metagenomic biosurfactant protein 1 (MBSP1). In addition, E. coli RosettaTM (DE3) strain cells transformed with the MBSP1 clone showed an increase in aliphatic hydrocarbon degradation. In this study, we described a single gene encoding a protein with marked tensoactive properties that can be produced in a host cell, such as Escherichia coli, without substrate dependence. Furthermore, MBSP1 has been demonstrated as the first protein with these characteristics described in the Archaea or Bacteria domains.


Assuntos
Proteínas de Bactérias/metabolismo , Halobacteriaceae/metabolismo , Metabolismo dos Lipídeos , Óleos/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Halobacteriaceae/classificação , Halobacteriaceae/genética , Hidrocarbonetos/metabolismo , Fases de Leitura Aberta , Filogenia , Conformação Proteica , Relação Estrutura-Atividade , Tensoativos/metabolismo
17.
Chem Biol Interact ; 317: 108962, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31982400

RESUMO

Quaternary ammonium compounds (e.g., benzalkonium chloride (BAC) and cetylpyridinium chloride (CPC)) constitute a group of cationic surfactants are widely used for personal hygiene and medical care despite the potential pulmonary toxicity. To examine whether BAC and CPC aerosols deposited in the alveolar region alter pulmonary function, we studied the effects on pulmonary surfactant using two-step in vitro models; cytotoxicity using A549 alveolar epithelial cell and changes in surface activity of the pulmonary surfactant monolayer using both Surfacten® and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). Cell viability was decreased with BAC and CPC dose-dependently. A comparison of cytotoxicity among BAC homologues with different length of alkyl chain showed that C16-BAC, which has the longest alkyl chain, was more cytotoxic than C12- or C14-BAC. Caspase-3/7 activity and cleaved form of caspase-3 and PARP were increased in BAC- and CPC-exposed cells. The elevated caspase-3/7 activity and their cleaved active forms were abolished by caspase-3-inhibitor. Furthermore, we examined the features of the surface pressure/trough area (π-A) isotherm by the Langmuir-Wilhelmy method and atomic force microscopy (AFM) images of lipid monolayers on a subphase containing BAC, CPC, or pyridinium chloride (PC, as a control). The π-A isotherms showed that addition of BAC or CPC yielded dose-dependent increases in surface pressure without compression, indicating that BAC and CPC expand the isotherm to larger areas at lower pressure. The collapse pressure diminished with increasing concentration of CPC. Topographic images indicated that BAC and CPC resulted in smaller condensed lipid domains compared to the control. Conversely, PC without hydrocarbon tail group, showed no cytotoxicity and did not change the isotherms and AFM images. These results indicate that BAC and CPC cause cell death via caspase-3-dependent apoptotic pathway in A549 cells and alter the alveolar surfactant activity. These effects can be attributed to the long alkyl chain of BAC and CPC.


Assuntos
Apoptose/efeitos dos fármacos , Compostos de Benzalcônio/farmacologia , Cetilpiridínio/farmacologia , Células Epiteliais/efeitos dos fármacos , Pulmão/citologia , Mucosa Respiratória/citologia , Células A549 , Compostos de Benzalcônio/química , Sobrevivência Celular/efeitos dos fármacos , Cetilpiridínio/química , Humanos , Tensoativos/metabolismo
18.
Artigo em Inglês | MEDLINE | ID: mdl-31941392

RESUMO

Effects of trehalose lipids produced from Rhodococcus erythropolis ATCC 4277 on phenanthrene (PHE) mineralization by two soil microorganisms were investigated. Biodegradation experiments were conducted, with and without the biosurfactant, in three batch systems: water, soil, and soil-water slurry. PHE sorption to the soil did not limit the mineralization by the test microorganisms, Pseudomonas strain R (PR) and Sphingomonas sp. strain P5-2 (SP5-2). Both microorganisms, however, demonstrated significant difference in the PHE mineralization capability in the systems. While SP5-2 mineralized PHE faster than PR in liquid culture, PR having more hydrophobic surface greatly exceeded SP5-2 in ability to access soil-sorbed PHE. While the addition of the biosurfactant little affected the apparent cell hydrophobicity of SP5-2, it substantially improved PHE mineralization by this strain in all systems tested. Contrary to SP5-2, the apparent cell hydrophobicity was significantly stimulated with increasing concentration of the biosurfactant for PR. However, the biosurfactant had no significant effect on PHE mineralization by this microorganism. The results demonstrated that the addition of the biosurfactant may have great potential for remediation of sites contaminated with polycyclic aromatic hydrocarbons but its effects and benefits may be dependent on characteristics of microorganisms involved and environmental conditions.


Assuntos
Glicolipídeos/metabolismo , Fenantrenos/metabolismo , Pseudomonas/metabolismo , Rhodococcus/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Trealose/metabolismo , Biodegradação Ambiental , Disponibilidade Biológica , Fenantrenos/análise , Solo/química , Poluentes do Solo/análise , Tensoativos/metabolismo
19.
J Am Soc Mass Spectrom ; 31(2): 366-378, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31922726

RESUMO

Gemini surfactants are a class of lipid molecules that have been successfully used in vitro and in vivo as nonviral gene delivery vectors. However, the biological fate of gemini surfactants has not been well investigated. In particular, the metabolism of gemini surfactants after they enter cells as gene delivery vehicles is unknown. In this work, we used a high-resolution quadrupole-Orbitrap mass spectrometry (Q-Exactive) instrument to detect the metabolites of three model gemini surfactants, namely, (a) unsubstituted (16-3-16), (b) with pyridinium head groups (16(Py)-S-2-S-16(Py)), and (c) substituted with a glycyl-lysine di-peptide (16-7N(GK)-16). The metabolites were characterized, and structures were proposed, based on accurate masses and characteristic product ions. The metabolism of the three gemini surfactants was very different as 16-3-16 was not metabolized in PAM 212 cells, whereas 16(Py)-S-2-S-16(Py) was metabolized primarily via phase I reactions, including oxidation and dealkylation, producing metabolites that could be linked to its observed high toxicity. The third gemini surfactant 16-7N(GK)-16 was metabolized mainly via phase II reactions, including methylation, acetylation, glucose conjugation, palmityl conjugation, and stearyl conjugation. The metabolism of gemini surfactants provides insight for future directions in the design and development of more effective gemini surfactants with lower toxicity. The reported approach can also be applied to study the metabolism of other structurally related gemini surfactants.


Assuntos
Alcenos/metabolismo , Técnicas de Transferência de Genes , Compostos de Amônio Quaternário/metabolismo , Tensoativos/metabolismo , Alcenos/análise , Animais , Linhagem Celular Tumoral , Portadores de Fármacos/análise , Portadores de Fármacos/metabolismo , Camundongos , Compostos de Amônio Quaternário/análise , Tensoativos/análise , Espectrometria de Massas em Tandem
20.
Chemosphere ; 245: 125559, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31841794

RESUMO

As a widely used detergent, anionic surfactant linear alkylbenzene sulfonates (LAS) is a common toxic pollutant in wastewater. In this study, Pseudomonas sp. strain H6 was isolated from activated sludge and municipal wastewater, which had good degradation effect on LAS. The results showed that strain H6 could grow with LAS as the sole carbon source. When the concentration of LAS was less than 100 mg/L, strain H6 could degrade more than 80% of the LAS within 24 h. Meanwhile, the growth of strain H6 increased with the increase of LAS concentration, reaching the maximum growth at the presence of 100 mg/L LAS. When the concentration of LAS was over 100 mg/L, strain H6's cell growth and degradation of LAS showed a downward trend due to the strong toxicity of LAS, and the degradation rate of LAS almost tended to zero with 500 mg/L LAS. Further mutagenesis analysis of strain H6 showed that positive mutation occurred under ultraviolet and nitrite mutagenesis with using ampicillin to increase the screening pressure, and the degradation rate of LAS was 44.91% higher than that of original strain.


Assuntos
Ácidos Alcanossulfônicos/metabolismo , Bactérias/metabolismo , Biodegradação Ambiental , Carbono/metabolismo , Mutagênese , Esgotos/microbiologia , Tensoativos/metabolismo , Águas Residuárias
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