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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117382, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31357053

RESUMO

Fourier transform infrared (FTIR) and Raman spectroscopic techniques were employed to analyze the biomolecular transitions and lipid accumulation in three freshwater green microalgal species, Monoraphidium contortum (M. contortum), Pseudomuriella sp. and Chlamydomonas sp. during various phases of their growth. Biomolecular transitions and lipid [hydrocarbons, triacylglycerides (TAGs)] accumulation within the microalgal cells were identified using second derivatives of the FTIR absorption spectroscopy. Second derivative analysis normalized and resolved the original spectra and led to the identification of smaller, overlapping bands. Both relative and absolute content of lipids were determined using the integrated band area. M. contortum exhibited higher accumulation of lipids than the other two species. The integrated band area of the vibrations from saturated (SFA) and unsaturated lipids (UFA) enabled quantification of fatty acids. The percentage of SFA and UFA was determined using GC, FTIR and Raman spectroscopy. From the spectral data, the order of increasing concentration of SFA among the three microalgal species was M. contortum > Chlamydomonas sp. >Pseudomuriella sp. The spectral results on fatty acids were consistent with the separation of lipids by gas chromatography. The results emphasized the significance of FTIR and Raman spectroscopic methods in monitoring the biomolecular transitions and rapid quantification of lipids, without the need for extraction of lipids.


Assuntos
Clorófitas , Lipídeos , Microalgas , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise Espectral Raman/métodos , Biocombustíveis/análise , Clorófitas/química , Clorófitas/metabolismo , Ácidos Graxos/análise , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Lipídeos/análise , Lipídeos/química , Microalgas/química , Microalgas/metabolismo
2.
J Agric Food Chem ; 67(34): 9569-9578, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31385495

RESUMO

Acetyl-CoA synthetase (ACS) plays a key role in microalgal lipid biosynthesis and acetyl-CoA industrial production. In the present study, two ACSs were cloned and characterized from the oleaginous microalga Chromochloris zofingiensis. In vitro kinetic analysis showed that the Km values of CzACS1 and CzACS2 for potassium acetate were 0.99 and 0.81 mM, respectively. Moreover, CzACS1 and CzACS2 had outstanding catalytic efficiencies (kcat/Km), which were 70.67 and 79.98 s-1 mM-1, respectively, and these values were higher than that of other reported ACSs. CzACS1 and CzACS2 exhibited differential expression patterns at the transcriptional level under various conditions. Screening a recombinant library of 52 transcription factors (TFs) constructed in the present study via yeast one-hybrid assay pointed to seven TFs with potential involvement in the regulation of the two ACS genes. Expression correlation analysis implied that GATA20 was likely an important regulator of CzACS2 and that ERF9 could regulate two CzACSs simultaneously.


Assuntos
Acetato-CoA Ligase/metabolismo , Clorófitas/enzimologia , Regulação Enzimológica da Expressão Gênica , Microalgas/enzimologia , Acetato-CoA Ligase/química , Acetato-CoA Ligase/genética , Biocatálise , Clorófitas/química , Clorófitas/genética , Cinética , Metabolismo dos Lipídeos , Microalgas/química , Microalgas/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
3.
J Microbiol Biotechnol ; 29(9): 1361-1368, 2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31434170

RESUMO

Codium fragile is an edible seaweed in Asian countries that has been used as a thrombolytic, anticoagulant, antioxidant, anti-inflammatory, and immune-stimulatory agent. Ginseng has also been known to maintain immune homeostasis and to regulate the immune system via enhancing resistance to diseases and microorganisms. In this study, anionic macromolecules extracted from C. fragile (CFAM) were orally administered with red ginseng extract (100 mg/kg body weight) to cyclophosphamide-induced immunosuppressed male BALB/c mice to investigate the immune-enhancing cooperative effect of Codium fragile and red ginseng. Our results showed that supplementing CFAM with red ginseng extract significantly increased spleen index, T- and B-cell proliferation, NK cell activity, and splenic lymphocyte immuneassociated gene expression compared to those with red ginseng alone, even though a high concentration of CFAM with red ginseng decreased immune biomarkers. These results suggest that CFAM can be used as a co-stimulant to enhance health and immunity in immunosuppressed conditions.


Assuntos
Adjuvantes Imunológicos/farmacologia , Clorófitas/química , Substâncias Macromoleculares/farmacologia , Panax/química , Extratos Vegetais/farmacologia , Adjuvantes Imunológicos/química , Animais , Ânions/isolamento & purificação , Ânions/farmacologia , Ciclofosfamida/toxicidade , Quimioterapia Combinada , Imunossupressão , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/genética , Linfócitos/citologia , Linfócitos/imunologia , Substâncias Macromoleculares/isolamento & purificação , Masculino , Camundongos Endogâmicos BALB C , Extratos Vegetais/administração & dosagem , Extratos Vegetais/química , Baço/imunologia
4.
Molecules ; 24(15)2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31366018

RESUMO

Catalytic conversion of actual biomass to valuable chemicals is a crucial issue in green chemistry. This review discusses on the recent approach in the levulinic acid (LA) formation from three prominent generations of biomasses. Our paper highlights the impact of the nature of different types of biomass and their complex structure and impurities, different groups of catalyst, solvents, and reaction system, and condition and all related pros and cons for this process.


Assuntos
Clorófitas/química , Produtos Agrícolas/química , Ácidos Levulínicos/síntese química , Lignina/química , Rodófitas/química , Biomassa , Catálise , Química Verde , Hidrólise , Monossacarídeos/química , Polissacarídeos/química , Solventes/química
5.
Mar Drugs ; 17(8)2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31374937

RESUMO

The outburst of microbial resistance to antibiotics creates the need for new sources of active compounds for the treatment of pathogenic microorganisms. Marine microalgae are of particular interest in this context because they have developed tolerance and defense strategies to resist the exposure to pathogenic bacteria, viruses, and fungi in the aquatic environment. Although antimicrobial activities have been reported for some microalgae, natural algal bioactive peptides have not been described yet. In this work, acid extracts from the microalga Tetraselmis suecica with antibacterial activity were analyzed, and de novo sequences of peptides were determined. Synthetic peptides and their alanine and lysine analogs allowed identifying key residues and increasing their antibacterial activity. Additionally, it was determined that the localization of positive charges within the peptide sequence influences the secondary structure with tendency to form an alpha helical structure.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Organismos Aquáticos/química , Clorófitas/química , Microalgas/química , Peptídeos/farmacologia , Sequência de Aminoácidos , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Bactérias/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Peptídeos/química , Peptídeos/isolamento & purificação , Estrutura Secundária de Proteína
6.
Carbohydr Polym ; 222: 115010, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31320102

RESUMO

Two sulfated polysaccharides (SPs), F2 and F3, isolated from Codium isthmocladum were found to contain galactose, sulfate, and pyruvate. The apparent molecular weights of F2 and F3 were determined to be 62 and 61 kDa, respectively. NMR spectroscopy combined with chemical analysis showed that F2 and F3 have the same structural features. However, F3 showed higher sulfate/sugar ratio (1/2.6) than F2 (1/4). F2 and F3 are essentially (1 → 3)-ß-D-galactans with some branching at C6. Pyruvylation occurs at O3 and O4, forming 3,4-O-(1-carboxyethylidene)-ß-D-Galp residues; some of these pyruvylated residues contain sulfate groups at C6. Some non-branching residues contain sulfate at C4. None of the SPs exhibited antioxidant activity. MTT results indicated that 1 mg/mL of both SPs about 40% of PANC-1 cell viability. At 10 µg/mL, F2 and F3 had 1.7-fold longer clotting times compared to that of Clexane® at the same concentration. The higher sulfate content of F3 is not a determining factor for pharmacological activities of galactans, considering that both F2 and F3 exerted the effects.


Assuntos
Anticoagulantes/farmacologia , Antioxidantes/farmacologia , Clorófitas/química , Galactanos/farmacologia , Alga Marinha/química , Anticoagulantes/química , Anticoagulantes/isolamento & purificação , Antioxidantes/química , Antioxidantes/isolamento & purificação , Sequência de Carboidratos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Galactanos/química , Galactanos/isolamento & purificação , Humanos , Piruvatos/química , Piruvatos/isolamento & purificação , Piruvatos/farmacologia , Ésteres do Ácido Sulfúrico/química , Ésteres do Ácido Sulfúrico/isolamento & purificação , Ésteres do Ácido Sulfúrico/farmacologia
7.
J Appl Microbiol ; 127(4): 1004-1017, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31260145

RESUMO

AIM OF THE STUDY: In this study, antibacterial and antibiofilm potential of sulphated polysaccharides (SPs) extracted from Chlamydomonas reinhardtii (Cr) was evaluated against Neisseria mucosa, Escherichia coli, Streptococcus sp. and Bacillus subtilis. METHODS AND RESULTS: Antibacterial potential of Cr-SPs was evaluated by agar-cup diffusion, time-kill and colony-forming ability (CFU), minimum inhibitory and bactericidal concentration assays. Antibiofilm potential was evaluated by biofilm inhibition, eradication, extracellular-DNA, metabolic activity and microscopy assays. Cr-SPs at 0·5 mg ml-1 showed 34·52, 48·6, 66·1 and 55·6% reduced CFU in B. subtilis, Streptococcus, N. mucosa and E. coli respectively. Minimum inhibitory concentration of Cr-SPs was as low as 480 µg ml-1 for Streptococcus, N. mucosa and 420 µg ml-1 for B. subtilis and E. coli. At 1 mg ml-1 , Cr-SPs showed 50% biofilm inhibition, whereas 4-8 mg ml-1 showed 100% inhibition. Cr-SPs also effectively dissolved preformed biofilms. Dose-dependent reduction in extracellular DNA revealed that Cr-SPs interacts with the extra polymeric substance of the biofilm and destroys them. Light microscopy reconfirmed the above results. CONCLUSION: Cr-SPs not only inhibited biofilm formation but also effectively dissolved preformed-biofilms. SIGNIFICANCE AND IMPACT OF THE STUDY: The current study showed the promising potential of Cr-SPs as antibiofilm agents. Further validation will help in developing Cr-SPs as natural antibiotics against biofilm-causing bacteria.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Chlamydomonas reinhardtii/química , Clorófitas/química , Polissacarídeos/farmacologia , Antibacterianos/química , Antibacterianos/isolamento & purificação , Bactérias/crescimento & desenvolvimento , Biofilmes/crescimento & desenvolvimento , Escherichia coli/metabolismo , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Sulfatos/química , Sulfatos/isolamento & purificação , Sulfatos/farmacologia
8.
Spectrochim Acta A Mol Biomol Spectrosc ; 222: 117216, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31176158

RESUMO

Advanced exploitation in the green synthesis of nanomaterials has received considerable attention in the recent years. So that, an eco-friendly approach is proposed for the synthesis of silver­silver chloride nanoparticles (Ag@AgCl-NPs) which does not require any external reducing & capping agents, organic solvent and external halide sources using an aqueous extract green marine alga (Chaetomorpha sp).In order to characterize the formation of Ag@AgCl-NPs, several instruments including UV-vis, FTIR, HR-TEM, EDS mapping, XRD, XPS, SAED and DLS were used. On the other hands, although numerous methods have been reported for the analysis of toxic Hg2+ in drinking water, development of simple, rapid, inexpensive, selective and sensitive sensors still remains a great challenge. Herein, the colorimetric sensor studies of this green synthesized Ag@AgCl-NPs showed an interesting feature for sensing of hazardous Hg2+ in water. The colorimetric assay is based on the concentration - dependent degradation of as-prepared Ag@AgCl-NPs in the presence of Hg2+. The detection limit of this affordable assay is 4.19 nM which is below the defined value by china agency and more importantly is below the defined by the U.S. Environmental Protection Agency for drinkable water.


Assuntos
Clorófitas/química , Mercúrio/análise , Nanopartículas Metálicas/química , Compostos de Prata/química , Prata/química , Poluentes Químicos da Água/análise , Colorimetria/métodos , Água Potável/análise , Química Verde/métodos , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Oxirredução , Compostos de Prata/síntese química
9.
Environ Sci Pollut Res Int ; 26(22): 22704-22722, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31172437

RESUMO

Monolithic algal green powder (MAGP) was fabricated based on the marine green macroalga Enteromorpha flexuosa. It was scrutinized by using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), Fourier transform infrared (FT-IR), point of zero charge (PHPZC), and Brunauer-Emmett-Teller (BET) surface area. The ability of Enteromorpha flexuosa to capture both crystal violet (CV) and methylene blue (MB) from aqueous solutions was evaluated. The influence of variable conditional parameters on CV dye and MB dye batch sorption was investigated. Results showed that percentage removal of 90.3% and 93.4% were obtained under optimum conditions of variables for CV and MB, respectively. Effect of microwave radiation on dye sorption was also appraised. Processing the sorption under microwave irradiation (microwave-enforced sorption, MES) increases mass transfer and a contact time as low as 1 min is sufficient under optimized conditions (exposure time and power) reaching the equilibrium. The reusability of MAGP sorbent was achieved for four cycles of sorption/desorption by using 0.5 M HCl. The ability of MAGP for cationic dyes removal from spiked tap water and petrochemical plant discharge wastewater samples was successfully registered. Ultimately, the displayed data showed a superior and excellent ability of algal powder to be exploited as a green, harmless, and effective sorbent for cationic dye removal.


Assuntos
Clorófitas/química , Corantes/química , Micro-Ondas , Poluentes Químicos da Água/química , Adsorção , Biomassa , Cátions , Violeta Genciana/química , Concentração de Íons de Hidrogênio , Cinética , Azul de Metileno , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química
10.
Mar Drugs ; 17(6)2019 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-31207947

RESUMO

Ulva lactuca is a green macro alga involved in devastating green tides observed worldwide. These green tides or blooms are a consequence of human activities. Ulva blooms occur mainly in shallow waters and the decomposition of this alga can produce dangerous vapors. Ulva lactuca is a species usually resembling lettuce, but genetic analyses demonstrated that other green algae with tubular phenotypes were U. lactuca clades although previously described as different species or even genera. The capacity for U. lactuca to adopt different phenotypes can be due to environment parameters, such as the degree of water salinity or symbiosis with bacteria. No efficient ways have been discovered to control these green tides, but the Mediterranean seas appear to be protected from blooms, which disappear rapidly in springtime. Ulva contains commercially valuable components, such as bioactive compounds, food or biofuel. The biomass due to this alga collected on beaches every year is beginning to be valorized to produce valuable compounds. This review describes different processes and strategies developed to extract these different valuable components.


Assuntos
Ulva/química , Animais , Biocombustíveis , Biomassa , Clorófitas/química , Humanos , Mar Mediterrâneo , Salinidade , Simbiose/fisiologia
11.
Carbohydr Polym ; 218: 355-370, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31221340

RESUMO

Ulvan, a sulphated polysaccharide located in the cell walls of green algae that possesses unique structural properties albeit its repeating unit shares chemical affinity with glycosoaminoglycans, such as hyaluronan and chondroitin sulphate, has been increasingly studied over the years for applications in the pharmaceutical field. The increasing knowledge on ulvan's chemical properties and biological activities has triggered its utilization in hybrid materials, given its potential efficacy in biomedical applications. In the present review, the use of ulvan in the design of different biomaterials, including membranes, particles, hydrogels, 3D porous structures and nanofibers, is presented. The applications of these structures may vary from drug delivery to wound dressing or bone tissue engineering. In this context, general information regarding the structure and chemical variability, extraction processes, physicochemical properties, and biological activities of ulvan is reported.


Assuntos
Materiais Biocompatíveis/farmacologia , Polissacarídeos/farmacologia , Bactérias/efeitos dos fármacos , Materiais Biocompatíveis/química , Sequência de Carboidratos , Clorófitas/química , Portadores de Fármacos/química , Hidrogéis/química , Membranas Artificiais , Nanoestruturas/química , Polissacarídeos/química , Tecidos Suporte/química
12.
Chemosphere ; 228: 351-359, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31042608

RESUMO

Harmful algae pollution in eutrophic waters represents one of the most serious problems in natural water environment. Adsorption assisted photocatalytic inactivation is often considered as a promising method to achieve the clean-up of harmful algae and the remediation of eutrophic water. Here, we synthesize the NPTiO2 (nitrogen and phosphorous doped TiO2)/C composites using a facile sol-gel method, and demonstrate successful achievement of efficient adsorption-photocatalytic performance via the in-situ formed carbides coated with NPTiO2 nanoparticles. We find that the composites have rough surfaces with porous structure, which can be tuned by the calcination temperature, and that such composites can be served to efficiently capture the algal cells. The N and P are successfully doped into the TiO2 crystal lattices, and the cooperation of carbides and NPTiO2 particles enhances significantly light absorption, while inhibiting the recombination of the photogenerated charge carriers. Among all the NPTiO2/C composites, the NPTiO2/C system calcinated at 550 °C shows the best photocatalytic performance for the algal inactivation, presenting a removal rate of 92.6% following 6 h visible light irradiation. The destruction of cell structures is clearly observed in the photocatalytic process. Interestingly, the metabolic activities are also disturbed by the photogenerated radicals, which accelerates the death of algal cells. Moreover, the NPTiO2/C composite can effectively remove the cytotoxins from water, rendering the composite and the doping strategy promising in the remediation practice for eutrophic waters.


Assuntos
Clorófitas/química , Nanopartículas/química , Titânio/química , Água/química , Adsorção , Catálise
13.
Int J Biol Macromol ; 134: 390-396, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31078599

RESUMO

The biomass from Enteromorpha prolifera is used to exploit and transfer this common green bloom algae into new value-added products. In this work, cellulose nanocrystals (CNCs) were first prepared with the cellulose extracted from the biomass of E. prolifera. Initially, cellulose was treated by alkali and bleaching treatments. Subsequently, CNCs were isolated by acid hydrolysis with different concentrations. Structural changes and crystallinity were characterized by Fourier transform infrared spectroscopy (FTIR) spectroscopy, X-ray diffraction (XRD) analysis and t thermogravimetric analysis. The crystallinity index and crystallite size of the prepared CNCs depended mainly on acid concentrations. TEM observation revealed that the CNCs obtained by hydrolysis with 60% acid (CNC60) exhibited a 'needle-like' nanocrystals with a length of 177 ±â€¯12 nm and width of 3 ±â€¯1 nm, indicating that the CNC60 had a high ratio aspect and could serve as reinforcement nanofiller. Further investigation showcased that the addition of CNC60 exhibited the best effect for enhancing the mechanical properties of bionanocomposite films derived from the water-soluble polysaccharides extracted from the biomass of E. prolifera. Therefore, a new strategy was offered in this study for the comprehensive utilization of E. prolifera biomass to fabricate them into high-strength film materials.


Assuntos
Materiais Biocompatíveis/química , Celulose/química , Clorófitas/química , Nanocompostos/química , Nanopartículas/química , Polissacarídeos/química , Materiais Biocompatíveis/isolamento & purificação , Biomassa , Módulo de Elasticidade , Nanocompostos/ultraestrutura , Permeabilidade , Polissacarídeos/isolamento & purificação , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Vapor , Resistência à Tração , Termogravimetria , Difração de Raios X
14.
Int J Biol Macromol ; 135: 152-162, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31125656

RESUMO

Marine algae wereprovedto begoodadsorbentsformany pollutants. In this work, Aegagropila Linnaei (Aegagropila L.) was treated with sodium hydroxideand sodium chlorite. The extracted cellulose content was 18.5%. It was functionalized with Dimethyl diallyl ammonium chloride and diallylamin co-polymer. The products were characterized using Fourier Transform Infra-Red (FT-IR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and thermogravimetric analyses (TGA). The samples were studied as adsorbents of methylene blue(MB) and acid blue 25(AB25) in a controlled batch system. The effect of salts concentration (KCl, NaCl, and CaCl2), adsorbent dosage, pH, contact time and initial dye concentration on the adsorption mechanism was discussed. At equilibrium, the adsorption of MB and AB25ontoextracted and functionalized cellulose reached 109 mg/g and 139 mg/g, respectively. Under the same conditions, the adsorption capacity of AB25 and MB onto unmodified Aegagropila L. was, only, 32 mg/g and 47 mg/g. The pseudo second-order kinetic equation exhibited the optimal fitting results. The mean free energy (E = 70.71 to 223.6 Kj/mol), calculated from Dubinin-Radushkevich isotherm, suggested a chemi-sorption mechanism. Overall, the results confirmed that the studied products could be considered as valuable bio-sorbents of dyes from contaminated waters.


Assuntos
Ânions/química , Cátions/química , Celulose/química , Clorófitas/química , Corantes/química , Poluentes Químicos da Água/química , Adsorção , Celulose/ultraestrutura , Concentração de Íons de Hidrogênio , Cinética , Modelos Químicos , Análise Espectral , Termogravimetria , Purificação da Água
15.
Mar Drugs ; 17(6)2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31142027

RESUMO

Recent studies have shown that marine algae represent a great source of natural compounds with several properties. The lipidic extract of the seaweed Chaetomorpha linum (Chlorophyta, Cladophorales), one of the dominant species in the Mar Piccolo of Taranto (Mediterranean, Ionian Sea), revealed an antibacterial activity against Vibrio ordalii and Vibrio vulnificus, common pathogens in aquaculture, suggesting its potential employment to control fish and shellfish diseases due to vibriosis and to reduce the public health hazards related to antibiotic use in aquaculture. This extract showed also an antioxidant activity, corresponding to 170.960 ± 16. mmol Trolox equivalent/g (oxygen radical absorbance capacity assay-ORAC) and to 30.554 ± 2.30 mmol Trolox equivalent/g (Trolox equivalent antioxidant capacity assay-TEAC). The chemical characterization of the extract, performed by 1D and 2D NMR spectroscopy, highlighted the presence of free, saturated (SAFAs), unsaturated (UFAs) and polyunsaturated (PUFAs) fatty acids. The high content of ω-6 and ω-3 PUFAs confirmed also by gas chromatography indicates the potentiality of this algal species in the production of fortified food. The antibacterial activity seems related to the presence of linolenic acid present at high density, while the antioxidant activity could be likely ascribable to molecules such as carotenoids and chlorophylls (characterized also by thin-layer chromatography), known for this property. The presence of polyhydroxybutyrate, a biopolymer with potentiality in the field of biodegradable bioplastics was also detected. The exploitation of C. linum for a future biotechnological application is also encouraged by the results from a first attempt of cultivating this species in an integrated multi-trophic aquaculture (IMTA) system.


Assuntos
Clorófitas/química , Lipídeos/química , Lipídeos/farmacologia , Compostos Fitoquímicos/química , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Bactérias/efeitos dos fármacos , Clorófitas/crescimento & desenvolvimento , Cromatografia em Camada Delgada , Ácidos Graxos/análise , Espectroscopia de Ressonância Magnética , Mar Mediterrâneo , Compostos Fitoquímicos/farmacologia , Pigmentos Biológicos/química
16.
Ecotoxicol Environ Saf ; 180: 430-438, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31112842

RESUMO

The potential of Dunaliella salina isolated from Sambhar Salt Lake (Rajasthan, India) for biosorption of hexavalent chromium Cr(VI) in aqueous solution has been examined under optimized culture conditions. The influence of various process parameters, such as pH (6-11), incubation time (48-120 h), metal concentration (5-25 mgL-1), inoculum dose (2-10% vv-1), and their combination effects during Cr(VI) sorbtion were analyzed by means of Response Surface Methodology (RSM) based on a 3-level Box-Behnken experiment design. Microalgae showed highest chromium biosorption with 66.4% efficiency at optimum pH (8.6) and 10% (vv-1) inoculum size within 120 h. The experimental data obtained were analyzed by analysis of variance (ANOVA) along with lower value of coefficient of variation (34%), indicated the well fitness of quadratic equation as proposed by response surface model. Involvement of the surface morphology of the microalgae biomass and elemental distribution was studied through Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopic (EDS), Fourier-transform infrared spectroscopy (FTIR) and X-ray Diffraction (XRD) analysis. The findings unequivocally corroborates that the novel microalgae inherits immense potential in alleviating the levels of toxic heavy metal, such as Cr(VI) from the hydrosphere at wide range of pH and metal concentrations. The present study provides a workable solution for bioremediation of hazardous heavy metals, in general, and Cr(VI) in specific from the industrial wastes like tannery effluents.


Assuntos
Clorófitas/crescimento & desenvolvimento , Cromo/análise , Lagos/química , Poluentes Químicos da Água/análise , Adsorção , Biodegradação Ambiental , Clorófitas/química , Concentração de Íons de Hidrogênio , Índia , Resíduos Industriais/análise , Modelos Teóricos
17.
Environ Sci Pollut Res Int ; 26(17): 17512-17519, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31025277

RESUMO

Phytoplankton assemblages were investigated in 2015 along the seasonal changes of the Genhe River in the Greater Hinggan Mountains. The survey was performed in June (spring), August (summer), and October (autumn) at nine sampling stations to study the community composition, abundance, and biodiversity. The results showed that 61 species belonging to 16 genera were identified, including Bacillariophyta of 31 species, Dinophyta 2 species, Cyanophyta 2 species, Chlorophyta 20 species, Chrysophyta 2 species, and Cryptophyta 1 species; Besides, Bacillariophyta are dominant species. Shannon-Wiener (H') and Pielou (J') indices indicated that phytoplankton community was stable. And these two indices were significantly lower in summer than in spring and autumn. Phytoplankton abundance and biomass show significant differences in each season. The total phytoplankton abundance (1122.3 × 104 ind/L) and biomass (6.5709 mg/L) in summer are much higher than that in spring and autumn. There were few species and low abundance and biomass in the upper reaches of Genhe River; this fact can be explained by the cold climate in the Greater Higgnan Mountains region. Canonical correspondence analysis (CCA) was used to analyze the data. It revealed that Fe3+, Cu2+, pH, and water temperature (WT) were responsible for most of the variation in space in the phytoplankton community. These environmental parameters play an essential role in the community structure variation of phytoplankton in the upper reaches of Genhe River, the strong association between phytoplankton community structure and ecological factors is varied in each season.


Assuntos
Clorófitas/química , Cianobactérias/química , Diatomáceas/classificação , Dinoflagelados/química , Fitoplâncton/classificação , Rios/química , Biodiversidade , Biomassa , China , Diatomáceas/química , Ecologia , Fitoplâncton/química , Estações do Ano , Temperatura Ambiente , Qualidade da Água
18.
Mar Drugs ; 17(4)2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31027312

RESUMO

Sulfated polysaccharides from marine algae have high potential as promising candidates for marine drug development. In this study, a homogeneous sulfated polysaccharide from the marine green alga Monostroma nitidum, designated MS-1, was isolated using water extraction and anion-exchange and size-exclusion chromatography. Results of chemical and spectroscopic analyses showed that MS-1 mainly consisted of →3)-α-l-Rhap-(1→ and →2)-α-l-Rhap-(1→ residues, with additional branches consisting of 4-linked ß-d-xylose, 4-/6-linked d-glucose, terminal ß-d-glucuronic acid, and 3-/2-linked α-l-rhamnose. Sulfate ester groups substituted mainly at C-2/C-4 of →3)-α-l-Rhap-(1→ and C-4 of →2)-α-l-Rhap-(1→ residues, slightly at C-2 of terminal ß-d-glucuronic residues. MS-1 exhibited strong anticoagulant activity in vitro and in vivo as evaluated by the activated partial thromboplastin time and thrombin time assays, and significantly decreased platelet aggregation. The anticoagulant activity mechanism of MS-1 was mainly attributed to strong potentiation thrombin by heparin cofactor-II, and it also hastened thrombin and coagulation factor Xa inhibitions by potentiating antithrombin-III. MS-1 possessed markedly thrombolytic activity evaluated by plasminogen activator inhibitior-1, fibrin degradation products, and D-dimer levels using rats plasma, and recanalization rate by FeCl3-induced carotid artery thrombosis in mice. MS-1 exhibited strong antithrombotic activity in vitro and in vivo evaluated by the wet weighs and lengths of thrombus, and thrombus occlusion time by electrically-induced carotid artery thrombosis in rats. These results suggested that MS-1 could be a promising marine drug for prevention and therapy of thromboembolic disease.


Assuntos
Anticoagulantes/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Clorófitas/química , Fibrinolíticos/farmacologia , Polissacarídeos/farmacologia , Sulfatos/farmacologia , Animais , Trombose das Artérias Carótidas/sangue , Trombose das Artérias Carótidas/induzido quimicamente , Humanos , Masculino , Camundongos , Agregação Plaquetária/efeitos dos fármacos , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Ratos , Ratos Sprague-Dawley , Sulfatos/química , Sulfatos/isolamento & purificação
19.
Anal Chim Acta ; 1066: 121-130, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31027526

RESUMO

A visual, rapid, and sensitive method for the detection of two algal metabolites, geosmin (GSM) and 2-methylisoborneol (2-MIB) using a competitive displacement technique based on molecular imprinted polymers (MIPs) and fluorescent tags was developed. In this method, fluorescent tags that bind to synthetic receptor sites of MIPs were designed and synthesised. In the presence of target analytes (geosmin and 2-methylisoborneol respectively), the tags are displaced leading to fluorescence signals. The MIPs were derived from the polymerisation of functional monomers and crosslinkers in the presence of suitable templates. Good to high binding capacities and selectivities were obtained with the MIPs. The displacement of fluorescent-tagged substrates from the respective MIPs by the target analytes enabled the quantitative detection of geosmin at concentrations as low as 0.38 µM (69 µg L-1), while the LOD for 2-methylisoborneol is 0.29 µM (48 µg L-1) without any cross-reactivity, non-specific (false-positive) binding, and matrix complications. Qualitative detection of geosmin and 2-methylisoborneol is also possible via visualisation of fluorescence using a hand held UV lamp, with LOD for geosmin and 2-methylisoborneol at 0.44 µM (80 µg L-1) and 0.35 µM (60 µg L-1), respectively. The sensitivity of the system can be improved with a pre-concentration step using the respective MIPs as a sorbent.


Assuntos
/análise , Clorófitas/química , Fluorescência , Impressão Molecular , Naftóis/análise , Polímeros/química , /metabolismo , Clorófitas/metabolismo , Cinética , Estrutura Molecular , Naftóis/metabolismo , Tamanho da Partícula , Polímeros/síntese química , Propriedades de Superfície
20.
Proc Biol Sci ; 286(1894): 20182231, 2019 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-30963882

RESUMO

Diets must satisfy the everyday metabolic requirements of organisms and can also serve as medicines to combat disease. Currently, the medicinal role of diets is much better understood in terrestrial than in aquatic ecosystems. This is surprising because phytoplankton species synthesize secondary metabolites with known antimicrobial properties. Here, we investigated the medicinal properties of phytoplankton (including toxin-producing cyanobacteria) against parasites of the dominant freshwater herbivore, Daphnia. We fed Daphnia dentifera on green algae and toxic cyanobacteria diets known to vary in their nutritional quality and toxin production, and an additional diet of Microcystis with added pure microcystin-LR. We then exposed Daphnia to fungal and bacterial parasites. Anabaena, Microcystis and Chlorella diets prevented infection of Daphnia by the fungal parasite Metschnikowia, while Nodularia toxins increased offspring production by infected hosts. In contrast to their medicinal effects against Metschnikowia, toxic phytoplankton generally decreased the fitness of Daphnia infected with the bacterial parasite, Pasteuria. We also measured the amount of toxin produced by phytoplankton over time. Concentrations of anatoxin-a produced by Anabaena increased in the presence of Metschnikowia, suggesting parasite-induced toxin production. Our research illustrates that phytoplankton can serve as toxins or medicines for their consumers, depending upon the identity of their parasites.


Assuntos
Daphnia/fisiologia , Daphnia/parasitologia , Aptidão Genética , Interações Hospedeiro-Parasita , Fitoplâncton , Animais , Clorófitas/química , Cianobactérias/química , Dieta , Fungos/fisiologia
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