Summary
Microalgal cultivation that takes advantage of solar energy is one of the most cost‐effective systems for the biotechnological production of biofuels, and a range of high value products, ...including pharmaceuticals, fertilizers and feed. However, one of the main constraints for the cultivation of microalgae is the potential contamination with biological pollutants, such as bacteria, fungi, zooplankton or other undesirable microalgae. In closed bioreactors, the control of contamination requires the sterilization of the media, containers and all materials, which increases the cost of production, whereas open pond systems severely limits the number of species that can be cultivated under extreme environmental conditions to prevent contaminations. Here, we report the metabolic engineering of Chlamydomonas reinhardtii to use phosphite as its sole phosphorus source by expressing the ptxD gene from Pseudomonas stutzeri WM88, which encodes a phosphite oxidoreductase able to oxidize phosphite into phosphate using NAD as a cofactor. Engineered C. reinhardtii lines are capable of becoming the dominant species in a mixed culture when fertilized with phosphite as a sole phosphorus source. Our results represent a new platform for the production of microalgae, potentially useful for both closed photobioreactors and open pond systems without the need for using sterile conditions nor antibiotics or herbicides to prevent contamination with biological pollutants.
As the skin is the main protective organ of the body, it is exposed to wounds or injuries which carry out a healing process during a period of approximately 15 days depending on the severity of the ...injury. In the present research, the development of chitosan-based hydrogels loaded with silver nanoparticles and calendula extract (Ch-AgNPs-Ce) was proposed. This can be used to fulfill the hemostatic, anti-infective, antibacterial, healing and anti-inflammatory functions through controlled release of the nanoparticles and calendula extract in substitution of commonly used drugs. The physical properties of the silver nanoparticles were analyzed by UV–visible spectroscopy, scanning and transmission electron microscopy, showing a size between 50 and 100 nm. The antibacterial properties were evaluated by the agar well diffusion method. Antimicrobial testing of the hydrogels showed that the inclusion of silver nanoparticles provides concentration-dependent antibacterial behavior against E. coli and S. aureus. The healing properties of the system were tested in two diabetic patients to whom said hydrogels were placed, obtaining a positive curative result after a few weeks. Therefore, it can be concluded that Ch-AgNPs-Ce hydrogels can achieve healing in chronic or exposed wounds after a period of time which can be used in alternative treatments in patients with poor healing capacity.
In recent years, the increase in antibiotic resistance demands searching for new compounds with antimicrobial activity. Phytochemicals found in plants offer an alternative to this problem. The genus ...Pelargonium contains several species; some have commercial use in traditional medicine such as
, and others such as
are little studied but have promising potential for various applications such as phytopharmaceuticals. In this work, we characterized the freeze-dried extracts (FDEs) of five tissues (root, stem, leaf, and two types of flowers) and the ethyl acetate fractions from leaf (Lf-EtOAc) and flower (Fwr-EtOAc) of
through the analysis by thin-layer chromatography (T.L.C.), gas chromatography coupled to mass spectrometry (GC-MS), phytochemicals quantification, antioxidant capacity, and antimicrobial activity. After the first round of analysis, it was observed that the FDE-Leaf and FDE-Flower showed higher antioxidant and antimicrobial activities compared to the other FDEs, for which FDE-Leaf and FDE-Flower were fractionated and analyzed in a second round. The antioxidant activity determined by ABTS showed that Lf-EtOAc and Fwr-EtOAc had the lowest IC
values with 27.15 ± 1.04 and 28.11 ± 1.3 µg/mL, respectively. The content of total polyphenols was 264.57 ± 7.73 for Lf-EtOAc and 105.39 ± 4.04 mg G.A./g FDE for Fwr-EtOAc. Regarding the content of flavonoid, Lf-EtOAc and Fw-EtOAc had the highest concentration with 34.4 ± 1.06 and 29.45 ± 1.09 mg Q.E./g FDE. In addition, the minimum inhibitory concentration (M.I.C.) of antimicrobial activity was evaluated: Lf-EtOAc and Fwr-EtOAc were effective at 31.2 µg/mL for
and 62.5 µg/mL for
, while for the
strain, Fwr-EtOAc presented 31.2 µg/mL of M.I.C. According to the GC-MS analysis, the main compounds were 1,2,3-Benzenetriol (Pyrogallol), with 77.38% of relative abundance in the Lf-EtOAc and 71.24% in the Fwr-EtOAc, followed by ethyl gallate (13.10%) in the Fwr-EtOAc and (Z)-9-Octadecenamide (13.63% and 6.75%) in both Lf-EtOAc and Fwr-EtOAc, respectively.
So far, several studies have focused on the synthesis of metallic nanoparticles making use of extracts from the fruit of the plants from the genus Capsicum. However, as the fruit is the edible, and ...highly commercial, part of the plant, in this work we focused on the leaves, a part of the plant that is considered agro-industrial waste. The biological synthesis of gold (AuNPs) and silver (AgNPs) nanoparticles using aqueous extracts of root, stem and leaf of
was evaluated, obtaining the best results with the leaf extract. Gold and silver nanoparticles synthesized using leaf extract (AuNPs-leaf and AgNPs-leaf, respectively) were characterized by UV-visible spectrophotometry (UV-Vis), Fourier Transform Infrared Spectroscopy with Attenuated Total Reflection (FTIR-ATR), X-ray Photoelectron Spectroscopy (XPS), Ultra Hight Resolution Scanning Electron Microscopy coupled to Energy-Dispersive X-ray spectroscopy (UHR-SEM-EDX) and Transmission Electron Microscopy (TEM), and tested for their antioxidant and antimicrobial activities. In addition, different metabolites involved in the synthesis of nanoparticles were analyzed. We found that by the use of extracts derived from the leaf, we could generate stable and easy to synthesize AuNPs and AgNPs. The AuNPs-leaf were synthesized using microwave radiation, while the AgNPs-leaf were synthesized using UV light radiation. The antioxidant activity of the extract, determined by ABTS, showed a decrease of 44.7% and 60.7% after the synthesis of the AuNPs-leaf and AgNPs-leaf, respectively. After the AgNPs-leaf synthesis, the concentration of polyphenols, reducing sugars and amino acids decreased by 15.4%, 38.7% and 46.8% in the leaf extract, respectively, while after the AuNPs-leaf synthesis only reducing sugars decreased by 67.7%. These results suggest that these groups of molecules are implicated in the reduction/stabilization of the nanoparticles. Although the contribution of these compounds in the synthesis of the AuNPs-leaf and the AgNPs-leaf was different. Finally, the AgNPs-leaf inhibited the growth of
,
,
and
All of them are bacterial strains of clinical importance due to their fast antibiotic resistance development.
The use of selenium nanoparticles (SeNPs) in the biomedical area has been increasing as an alternative to the growing bacterial resistance to antibiotics. In this research, SeNPs were synthesized by ...green synthesis using ascorbic acid (AsAc) as a reducing agent and methanolic extract of
L. flowers as a stabilizer. Characterization of SeNPs was performed by UV-vis spectrophotometry, infrared spectrophotometry (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) techniques. SeNPs of 40-60 nm and spherical morphologies were obtained. The antibacterial activity of marigold extracts and fractions was evaluated by disk diffusion methodology. The evaluation of SeNPs at different incubation times was performed through the colony-forming unit (CFU) count, in both cases against
,
, and
bacteria. Partial antibacterial activity was observed with methanolic extracts of marigold leaves and flowers and total inhibition with SeNPs from 2 h for
, 1 h for
, and 30 min for
In addition, SeNPs were found to exhibit antioxidant activity. The results indicate that SeNPs present a potentiated effect of both antimicrobial and antioxidant activity compared to the individual use of marigold extracts or sodium selenite (Na
SeO
). Their application emerges as an alternative for the control of clinical pathogens.
Biosynthesized silver nanoparticles (AgNPs) are widely used in varied applications, which are morphology dependent. Consequently, a morphology-controlled synthesis is mandatory. Although there are ...several studies focused on the plant extract-based biosynthesis of metallic nanoparticles, the use of extracts obtained from agro-wastes is scant. Furthermore, information regarding morphology modification through the use of additional agents is even more scarce. Thus, in this study, AgNPs were synthesized using a malt extract (ME) obtained from an artisanal beer brewing process residue. Additionally, sodium chloride (NaCl), gum arabic (GA), and talc (T) were used in an attempt to modify the morphology of AgNPs. XRD, DLS, SEM, and TEM results demonstrate that stable AgNPs of different sizes and shapes were synthesized. FTIR, HPLC analysis, and the quantification of total proteins, free amino acids, reducing sugars, and total polyphenols before and after AgNPs synthesis showed that ME biomolecules allowed them to act as a source of reducing and stabilizing agents. Therefore, this study provides evidence that ME can be successfully used to biosynthesize AgNPs. Additionally, the antibacterial activity of AgNPs against Gram-negative and Gram-positive bacteria was evaluated. Results indicate that AgNPs show a higher antibacterial activity against Gram-positive bacteria.
In recent years, crop production has expanded due to the variety of commercially available species. This increase in production has led to global competition and the search for biostimulant products ...that improve crop quality and yield. At the same time, agricultural products that protect against diseases caused by phytopathogenic microorganisms are needed. Thus, the green synthesis of selenium nanoparticles (SeNPs) is a proposal for achieving these needs. In this research, SeNPs were synthesized from methanolic extract of Amphipterygium glaucum leaves, and chemically and biologically characterized.
The characterization of SeNPs was conducted by ultraviolet-visible spectrophotometry (UV-Vis), scanning electron microscopy (SEM), electron microscopy transmission (TEM), Dynamic Light Scattering (DLS), energy dispersion X-ray spectroscopy (EDX), and infrared spectrophotometry (FTIR) techniques. SeNPs with an average size of 40-60 nm and spherical and needle-shaped morphologies were obtained. The antibacterial activity of SeNPs against Serratia marcescens, Enterobacter cloacae, and Alcaligenes faecalis was evaluated. The results indicate that the methanolic extracts of A. glaucum and SeNPs presented a high antioxidant activity. The biostimulant effect of SeNPs (10, 20, 50, and 100 µM) was evaluated in vinca (Catharanthus roseus), and calendula (Calendula officinalis) plants under greenhouse conditions, and they improved growth parameters such as the height, the fresh and dry weight of roots, stems, and leaves; and the number of flowers of vinca and calendula.
The antibacterial, antioxidant, and biostimulant properties of SeNPs synthesized from A. glaucum extract demonstrated in this study support their use as a promising tool in crop production.
Obesity is an excessive accumulation of fat that exacerbates the metabolic and inflammatory processes. Studies associate these processes with conditions and dysregulation in the intestinal tract, ...increased concentrations of lipopolysaccharides (LPSs) in the blood, differences in the abundance of intestinal microbiota, and the production of secondary metabolites such as short-chain fatty acids. β-Caryophyllene (BCP) is a natural sesquiterpene with anti-inflammatory properties and with the potential purpose of fighting metabolic diseases. A diet-induced obesity model was performed in 16-week-old C57BL/6 mice administered with BCP 50 mg/kg. A reduction in the expression of Claudin-1 was observed in the group with a high-fat diet (HFD), which was caused by the administration of BCP; besides BCP, the
and
decreased between the groups with a standard diet (STD) vs. HFD. Nevertheless, the use of BCP in the STD increased the expression of these
with respect to fatty acids; a similar effect was observed, in the HFD group that had a decreasing concentration that was restored with the use of BCP. The levels of endotoxemia and serum leptin increased in the HFD group, while in the HFD + BCP group, similar values were found to those of the STD group, attributing the ability to reduce these in conditions of obesity.
The synthesis of
cis
and
trans
geometrical isomers of platinum(
ii
) complexes with a symmetric N-heterocyclic carbene ligand (
Me
NHC) is reported. These complexes were obtained from ...1,3-dimethylimidazolium-2-carboxylate, a masked NHC precursor. Their cytotoxicity, oxidative nature, and antibacterial behavior were investigated. The highest cytotoxic effect (IC
50
= 1.21 μM) was observed with the
cis
-Pt(
Me
NHC)
2
Cl
2
complex in the cervix cancerous cell line HeLa.
Cis
- and
trans
-NHC-Pt(
ii
) isomers from the masked carbene 1,3-dimethylimidazolium-2-carboxylate: the relevance of isomerism in the biological activity.
This research aimed to develop nanosuspensions as carriers of Annona muricata acetogenins (ACGs) using different concentrations of soy lecithin (SL), hydroxypropyl-β-cyclodextrin (βCD) and the ...dispersion method (low agitation, middle agitation and ultrasound) on particle size and polydispersity index (PDI). A response surface analysis was performed to find an optimized, validated and characterized nanosuspension (OβCDSL-ACGs-NSps) and to measure its antibacterial activity. The best conditions to formulate OβCDSL-ACGs-NSps with spherical nanoparticles (133.77 nm), PDI (0.20) and good stability (−37 mV) were 10 mg/mL SL, 0.16% βCD and ultrasound as a dispersion method. Nanoparticles from OβCDSL-ACGs-NSps exhibited a high entrapment (85.33%) and encapsulation efficiency (56.09%). The highest release (84.15%) of ACGs was observed until 36 h. OβCDSL-ACGs-NSps also showed significant antibacterial inhibition against E. faecalis (87%) and L. monocytogenes (75%) at 320 µg/mL. βCDSL-ACGs-NSps is an attractive and promising alternative to improve the solubility and bioavailability of ACGs in pharmaceutical applications.
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