•How temperature and KOH concentration influence on the carotenoids extraction.•How different polarity solvents influence on the recovery.•To establish a standard method for all microalgae is not ...possible.
Microalgae are an interesting source of natural pigments that have valuable applications. However, further research is necessary to develop processes that allow us to achieve high levels of carotenoid recovery while avoiding degradation. This work presents a comprehensive study on the recovery of carotenoids from several microalgae genera, optimizing carotenoid extraction using alkaline saponification at various temperatures and KOH concentrations. Results show that I. galbana requires a temperature of 60 °C and <10% KOH, N. gaditana and K. veneficum require 60 °C and no saponification, P. reticulatum requires 40 °C and 10% KOH, T. suecica and H. pluvialis require 25 °C and 40% KOH while C. sp. and S. almeriensis require 80 °C and 40% KOH. The influence of the solvent on carotenoid recovery was also studied. In general terms, an ethanol:hexane:water (77:17:6 v/v/v) mixture results in good yields.
► A methodology to recirculate medium in microalgae cultures is developed. ► The most adequate sterilization method is established. ► The recirculation reduces the demand of nutrients cutting costs ...in the process. ► N. gaditana continuous cultures were maintained using the recirculated medium. ► The biomass biochemical composition resulted of high interest for aquaculture.
Nannochloropsis gaditana is a good producer of proteins and valuable fatty acids for aquaculture. Recycling of culture medium is interesting for microalgae commercial production as it cuts costs and prevents environmental contamination. The recycled medium must be sterilized to prevent the buildup of unwanted metabolites and microorganisms. We tested several sterilization methods: filtration, ozonation, chlorination, addition of hydrogen peroxide and heating. Results showed that the most successful method is ozonation lowering the bacterial load to 1.9103CFUs/mL, which is 1000-fold and 10-fold lower than the supernatant obtained after harvesting and the initial filtered medium, respectively. Continuous cultures of N. gaditana were grown using this recirculated supernatant. A maximum biomass productivity of 0.8g/L/d composed of ∼50% proteins and 40% lipids with more than 3%d.w. EPA was obtained making this biomass very interesting for aquaculture.
•A low-cost medium for Nannochloropsis gaditana culture is developed.•Agricultural fertilizers are used as alternative nutrient sources.•A reduction in the amount of nutrients needed to prepare the ...medium was achieved.•A high-quality biomass, suitable for aquaculture applications is produced.
Nannochloropsis gaditana is a microalga with a high nutritional value and a protein and polyunsaturated fatty acid (PUFA) content that makes it interesting as a feed in aquaculture. To maximize its productivity and nutritional value in large-scale culture, a well-known commercial medium was optimized to the most favorable nutrient level using commercial fertilizers. Optimal growth conditions were obtained in the alternative fertilizer-based medium at a nitrogen concentration of 11.3mM, a phosphorus concentration of 0.16mM, and a micronutrient concentration of 30μLL−1. This alternative medium allowed to obtain a biomass concentration similar to that achieved when using the commercial formula but with a reduction in Cu, Fe, and Mo content of 71%, 89%, and 99%, respectively. A maximum biomass productivity of 0.51gL−1d−1 was obtained. The eicosapentaenoic acid and protein contents of the biomass were 2.84% and 44% of dry weight, respectively.
•Multi-step extraction processes for carotenoids, fatty acids and APDs were assessed.•Each step was optimized for dinoflagellates using previously reported methodologies.•Total recoveries were 97% ...for carotenoids, 80% for fatty acids and 100% for APDs.
Sustainable dinoflagellate microalgae-based bioprocess designed to produce secondary metabolites (SMs) with interesting bioactivities are attracting increasing attention. However, dinoflagellates also produce other valuable bioproducts (e.g polyunsaturated fatty acids, carotenoids, etc.) that could be recovered and should therefore be taken into account in the bioprocess. In this study, biomass of the marine dinoflagellate microalga Amphidinium carterae was used to assess and optimise three different methods in order to obtain three families of high-value biochemical compounds present in the biomass. The existing processes encompassed a multi-step extraction process for carotenoids, fatty acids and APDs individually and are optimized for the integral valorization of raw A. carterae biomass, with SMs being the primary target compounds. Total process recovery yields were 97% for carotenoids, 80% for total fatty acids and 100% for an extract rich in APDs (not purified).
Glioblastomas (GBM) are highly radioresistant and lethal brain tumors. Ionizing radiation (IR)-induced DNA double-strand breaks (DSBs) are a risk factor for the development of GBM. In this study, we ...systematically examined the contribution of IR-induced DSBs to GBM development using transgenic mouse models harboring brain-targeted deletions of key tumor suppressors frequently lost in GBM, namely Ink4a, Ink4b, Arf and/or PTEN. Using low linear energy transfer (LET) X-rays to generate simple breaks or high LET HZE particles (Fe ions) to generate complex breaks, we found that DSBs induce high-grade gliomas in these mice which, otherwise, do not develop gliomas spontaneously. Loss of Ink4a and Arf was sufficient to trigger IR-induced glioma development but additional loss of Ink4b significantly increased tumor incidence. We analyzed IR-induced tumors for copy number alterations to identify oncogenic changes that were generated and selected for as a consequence of stochastic DSB events. We found Met amplification to be the most significant oncogenic event in these radiation-induced gliomas. Importantly, Met activation resulted in the expression of Sox2, a GBM cancer stem cell marker, and was obligatory for tumor formation. In sum, these results indicate that radiation-induced DSBs cooperate with loss of Ink4 and Arf tumor suppressors to generate high-grade gliomas that are commonly driven by Met amplification and activation.
The purpose of this study was to develop an economical agricultural fertilizer-based medium for the mass production of
Isochrysis galbana
Parke, a marine microalga producing docosahexaenoic acid ...(DHA) and considered an excellent feed for use in aquaculture. Different fertilizers were used to replace the main nutrients, nitrogen and phosphorus, and the micronutrients of the well-known commercial medium, ALGAL. The obtained results showed that
I. galbana
preferred nitrate, instead of ammonium, as the nitrogen source and phosphate as the phosphorus source. Nonetheless, a nitrate concentration above 4 mM inhibited cell growth. The alternative medium proposed achieved a biomass productivity 22% higher than that for the ALGAL medium, reducing the medium’s contribution to the overall biomass cost by over 95%, with protein, lipid, carbohydrate, and DHA contents at 44, 36, 25, and 1.47% of dry weight, respectively, thus providing a cheaper biomass with excellent nutritional value for use in aquaculture.
Background
The aim of this randomized clinical trial was to evaluate the effect of diode laser photobiomodulation (PBM) on post‐surgical healing, inflammation and implant stability.
Methods
Forty ...dental implants were inserted into 13 patients. The implants were randomly divided into two groups. The test group (PBM+) underwent two sessions of PBM (combined diode laser of 630 and 808 nm), the first of which after surgery, and the second, 7 days after the surgical procedure. The control group (PBM−) received simulated laser treatment. The implant stability quotient (ISQ) was determined immediately after the surgical procedure, and 7 days, 4 and 8 weeks later. Post‐surgical inflammation was assessed following the criteria described by Bloemen and Cols. Healing was calculated using the healing index (HI).
Results
No differences were found in terms of the mean values of implant stability between the test and control groups over time. Only two of the implants (18.2%) from the PBM− group were classified with the maximum healing index (HI = 5), whereas in the PBM+ group, nine implants (45%) were classified with the aforementioned index (P < 0.0001). Using the logistic regression, it was determined that the non‐application of the laser in the PBM− group caused an OR of 4.333 times of presenting inflammation (IC95% 1.150–16.323; P = 0.030).
Conclusions
The application of 808 nm infra‐red laser for bone tissue, and 630 nm for mucosal tissue in two sessions is considered to be an effective way of reducing inflammation and improving early healing. More studies are needed to confirm these results.
The existence of multiple subclasses of Type Ia supernovae (SNe Ia) has been the subject of great debate in the last decade. One major challenge inevitably met when trying to infer the existence of ...one or more subclasses is the time consuming, and subjective, process of subclass definition. In this work, we show how machine learning tools facilitate identification of subtypes of SNe Ia through the establishment of a hierarchical group structure in the continuous space of spectral diversity formed by these objects. Using deep learning, we were capable of performing such identification in a four-dimensional feature space (+1 for time evolution), while the standard principal component analysis barely achieves similar results using 15 principal components. This is evidence that the progenitor system and the explosion mechanism can be described by a small number of initial physical parameters. As a proof of concept, we show that our results are in close agreement with a previously suggested classification scheme and that our proposed method can grasp the main spectral features behind the definition of such subtypes. This allows the confirmation of the velocity of lines as a first-order effect in the determination of SN Ia subtypes, followed by 91bg-like events. Given the expected data deluge in the forthcoming years, our proposed approach is essential to allow a quick and statistically coherent identification of SNe Ia subtypes (and outliers). All tools used in this work were made publicly available in the python package Dimensionality Reduction And Clustering for Unsupervised Learning in Astronomy (dracula) and can be found within COINtoolbox (https://github.com/COINtoolbox/DRACULA).
Protein-protein interaction networks (PPINs) are static representations of protein connections in which topological features such as subgraphs (communities) may contain proteins functionally related, ...revealing an additional layer of interactome complexity. We created two PPINs from the secretomes of a paired set of murine melanocytes (a normal melanocyte and its transformed phenotype). Community structures, identified by a graph clustering algorithm, resulted in the identification of subgraphs in both networks. Interestingly, the underlying structure of such communities revealed shared and exclusive proteins (core and exclusive nodes, respectively), in addition to proteins that changed their location within each community (rewired nodes). Functional enrichment analysis of core nodes revealed conserved biological functions in both networks whereas exclusive and rewired nodes in the tumoral phenotype network were enriched in cancer-related processes, including TGFβ signaling. We found a remarkable shift in the tumoral interactome, resulting in an emerging pattern which was driven by the presence of exclusive nodes and may represent functional network motifs. Our findings suggest that the rearrangement in the tumoral interactome may be correlated with the malignant transformation of melanocytes associated with substrate adhesion impediment. The interactions found in core and new/rewired nodes might potentially be targeted for therapeutic intervention in melanoma treatment.
Malignant transformation is a result of synergistic action of multiple molecular factors in which genetic alterations as well as protein expression play paramount roles. During oncogenesis, cellular crosstalk through the secretion of soluble mediators modulates the phenotype of transformed cells which ultimately enables them to successfully disrupt important signaling pathways, including those related to cell growth and proliferation. Therefore, in this work we profiled the secretomes of a paired set of normal and transformed phenotypes of a murine melanocyte. After assembling the two interactomes, clusters of functionally related proteins (network communities) were observed as well as emerging patterns of network rewiring which may represent an interactome signature of transformed cells. In summary, the significance of this study relies on the understanding of the repertoire of ‘normal’ and ‘tumoral’ secretomes and, more importantly, the set of interacting proteins (the interactome) in both of these conditions, which may reveal key components that might be potentially targeted for therapeutic intervention.
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•Interactomes were assembled for normal and tumoral (murine melanoma) secretomes.•Communities were identified in both networks, revealing clusters of functionally related proteins.•Tumoral network were mainly enriched in cancer-related processes, including TGFβ signaling.•These subgraphs may represent functional network motifs.•An emerging (rewired) pattern in tumoral interactome was driven by exclusive nodes.
The protein A13-2 was obtained from
strains isolated from the Papaloapan watershed region (Oaxaca, Mexico). The cytotoxic activity of parasporal inclusions was studied against breast cancer cell line ...(MCF-7) and normal cell (human peripheral blood mononuclear cells). The MTT, the formation of reactive species, nitric oxide, free cell DNA, and the type of death cellular were assessed. The protein A13-2 shows the highest cytotoxic activity against MCF-7 (13% cell viability at 6 µg/mL), the extracellular DNA increases, and it shows no stress for reactive species or nitric oxide. Besides, the A13-2 parasporin shows no toxicity to peripheral blood mononuclear cells, and it does not generate changes in nitric oxide levels or free cell DNA. Due to that, the cytotoxic effect of A13-2 was specific for MCF-7, and it does not affect normal cells. According to microscopy and flow cytometry, A13-2 parasporin leads to the death of MCF-7 cells by late apoptosis together with necrosis and without allowing the triggering of the survival mechanisms. When analyzed together, our results show for the first time that the A13-2 protein isolated from Mexican strains of
preferentially kills MCF- 7 (cancer cells) over HEK 293 and PBMC cell lines (normal cells), thus representing a promising alternative for the treatment of cancer breast.
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