243 research outputs found

    Autotrophic and Heterotrophic Growth Conditions Modify Biomolecole Production in the Microalga Galdieria sulphuraria (Cyanidiophyceae, Rhodophyta)

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    Algae have multiple similarities with fungi, with both belonging to the Thallophyte, a polyphyletic group of non-mobile organisms grouped together on the basis of similar characteristics, but not sharing a common ancestor. The main difference between algae and fungi is noted in their metabolism. In fact, although algae have chlorophyll-bearing thalloids and are autotrophic organisms, fungi lack chlorophyll and are heterotrophic, not able to synthesize their own nutrients. However, our studies have shown that the extremophilic microalga Galderia sulphuraria (GS) can also grow very well in heterotrophic conditions like fungi. This study was carried out using several approaches such as scanning electron microscope (SEM), gas chromatography/mass spectrometry (GC/MS), and infrared spectrophotometry (ATR-FTIR). Results showed that the GS, strain ACUF 064, cultured in autotrophic (AGS) and heterotrophic (HGS) conditions, produced different biomolecules. In particular, when grown in HGS, the algae (i) was 30% larger, with an increase in carbon mass that was 20% greater than AGS; (ii) produced higher quantities of stearic acid, oleic acid, monounsaturated fatty acids (MUFAs), and ergosterol; (iii) produced lower quantities of fatty acid methyl esters (FAMEs) such as methyl palmytate, and methyl linoleate, saturated fatty acids (SFAs), and poyliunsaturated fatty acids (PUFAs). ATR-FTIR and principal component analysis (PCA) statistical analysis confirmed that the macromolecular content of HGS was significantly different from AGS. The ability to produce different macromolecules by changing the trophic conditions may represent an interesting strategy to induce microalgae to produce different biomolecules that can find applications in several fields such as food, feed, nutraceutical, or energy production

    Into the Wild: Parallel Transcriptomics of the Tsetse-Wigglesworthia Mutualism within Kenyan Populations

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    Tsetse flies (Diptera: Glossinidae) have medical significance as the obligate vectors of African trypanosomes. In addition, tsetse harbor a simple gut microbiota. A predominant gut microbiota member, the Gammaproteobacterium Wigglesworthia spp., has coevolved with tsetse for a significant portion of Glossina radiation proving critical to tsetse fitness. Although multiple roles have been described for Wigglesworthia within colony flies, little research has been dedicated towards functional characterization within wild tsetse. Here, dual RNA-Seq was performed to characterize the tsetse-Wigglesworthia symbiosis within flies captured in Nguruman, Kenya. A significant correlation in Gene Ontology (GO) distribution between tsetse and Wigglesworthia was observed, with homogeneous enrichment in metabolic and transport categories, likely supporting a hallmark of the symbiosis-bidirectional metabolic exchange. Within field flies, highly transcribed Wigglesworthia loci included those involved in B vitamin synthesis and in substrate translocation, including amino acid transporters and multidrug efflux pumps, providing a molecular means for interaction. The universal expression of several Wigglesworthiaand G. pallidipes orthologs, putatively involved in nutrient provisioning and resource allocation, was confirmed in sister tsetse species. These transcriptional profiles varied through host age and mating status likely addressing varying symbiont demands and also confirming their global importance within Glossina. This study, not only supports symbiont nutrient provisioning roles, but also serves as a foundation for insight into novel roles and molecular mechanisms associated with vector–microbiota interactions. The role of symbiont B vitamin provisioning towards impacting host epigenetics is discussed. Knowledge of vector–microbiota interactions may lead to the discovery of novel targets in pest control

    Cyanidiophyceae in Iceland: Plastid rbcL gene elucidates origin and dispersal of extremophilic Galdieria sulphuraria and G. maxima (Galdieriaceae, Rhodophyta)

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    The Cyanidiophyceae are a group of unicellular organisms that diverged from ancestral red algae around 1.3 billion years ago. Present-day species are restricted to hot springs and geothermal habitats from around the world. Because of discontinuous geothermal environments, the distribution patterns and dispersal modes of the cyanidiophycean species are poorly understood. Iceland is the third largest island in the Atlantic Ocean and has intense underground volcanic activity that generates broad hydrothermal areas with different ecological conditions that are excellent for thermoacidophilic microfloral development. We analyzed populations to address the Icelandic cyanidiophycean biodiversity and dispersal. A global rbcL phylogeny showed two main populations inhabiting Iceland, Galdieria sulphuraria and G. maxima. Their areas of distribution are not completely superimposed because they coexisted only in New Zealand, Kamchatka (Russia), Japan, and Iceland. Because of the strong monophyly of Icelandic species with Japanese and Russian species, we hypothesized an origin and dispersion of Icelandic G. suphuraria and G. maxima from northeastern Asia. On the basis of network analysis of rbcL haplotypes, it is likely that the southwestern region of Iceland is the diversity center of both G. sulphuraria and G. maxima

    TOWARDS BENZ[A]ANTHRACENE XENOME ELUCIDATION IN PLANTS AND GREEN MICROALGAE

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    In only 12,000 years the Homo sapiens sapiens has completely modified the face of the Earth. The human pressure on the atmosphere, water and soil has been accelerate from the industrial revolution from which chemicals and energy have been released in the environment. Therefore, chemical environmental pollution and world climate changes are two of the main concerns that modern human must deal. Among chemicals released in the ecosystem the polycyclic aromatic hydrocarbon (PAHs) have gathered significant environment concerns for their detrimental biological effects, toxicity, mutagenicity, and carcinogenicity. The distribution of PAHs in the three environment compartments is related to the number of fused benzene rings. Two or three benzene rings have been occurring in the atmosphere whereas 5 or more rings are largely bounds in the soil particles. Intermediate, 4-rings, such as benz(a)anthracene (B[a]A) are partitioned between air and soil. The molecular mechanism involved to degrade PAHs into less toxic compounds by bacteria and fungi in soil has been elucidated. On the other hands, the metabolism of PAHs in plant and microalgae remain unknown. Signalling, transport, biotransformation of PAHs to less toxic molecules and compartmentalization are the main steps involved for their detoxification in photosynthetic cell. The expression of genes involved in these xenobiotics detoxification steps constitutes the xenome. The final aim of this work is to determine the B[a]A xenome in plants of tomato and in microalgae. So far, we have assessed the ability of tomato plants to grow in vitro and take up the B[a]A. Tomato seedlings were transplanted to MS medium added with 50 and 100 ÎĽg g -1 B[a]A and cultivated for 30 days. The detection of B[a]A in shoots infer a translocation from roots to shoots. However, the content of the PAH in shoots was much lower than in the root apparatus indicating that B[a]A was translocated very little from roots to shoots. The identification of microalgae species B[a]A capable of growing in presence of has been performed on 14 different species belonging to the genera Chlorella, Scenedesmus, Chlamydomonas, Ankistrodesmus, Botriococcus and Selenastrum, with six different concentrations of B[a]A. Four microalgae species showed a growth inhibition percentage less than 50% in a medium containing 43.8 ÎĽM B[a]A. The capacity to degrade B[a]A and affect the photosynthetic pigment content has been evaluated in the identified microalgae grown for 21 days in the medium containing B[a]A. The four microalgae strains reached 90% B[a]A degradation. Then, in silico analysis was carried out on C. reinhardtii proteome to identify potential laccase involved in the degradation process. Finally, the response of intracellular and extracellular activity in the absence and presence of the B[a]A was analysed by ABTS and 2,6-DMP assays

    Switchable Solvent Selective Extraction of Hydrophobic Antioxidants from Synechococcus bigranulatus

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    Hydrophobic molecules, in particular, carotenoids, have been directly extracted from Synechococcus bigranulatus ACUF680 by means of secondary amine switchable solvent N-ethylbutylamine (EBA) without any other pretreatment. EBA was able to extract hydrophobic molecules from both fresh and frozen biomass at the same extent of the conventional procedure (about 20% of dry biomass). In particular, selective extraction of a zeaxanthin-enriched fraction (green fraction, GF) and a β-carotene-enriched fraction (orange fraction, OF) was obtained. The ratio between zeaxanthin and β-carotene was 4.4 ± 1.5 for GF, 0.07 ± 0.06 for OF, and about 1 for conventional extraction. These fractions showed in vitro antioxidant activity (IC50 values of 0.056 ± 0.013 and 0.024 ± 0.008 mg mL-1 for GF and OF, respectively) and biocompatibility on immortalized cells. Moreover, OF and GF were able to protect cells from oxidative stress, both before and after thermal treatment. Results clearly indicate that EBA is a good candidate to specifically extract β-carotene and zeaxanthin from the wet biomass of S. bigranulatus without affecting their biological activity. Skipping energy-intensive operations to break the cells and using either fresh or frozen biomass may be the driving factors to use EBA switchable solvent on an industrial scale

    Walking the walk: a phenomenological study of long distance walking

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    Evidence suggests that regular walking can elicit significant psychological benefits although little evidence exists concerning long distance walking. The purpose of this study was to provide detailed accounts of the experiences of long distance walkers. Phenomenological interviews were conducted with six long distance walkers. Data were transcribed verbatim before researchers independently analyzed the transcripts. Participants reported a cumulative effect with positive feelings increasing throughout the duration of the walk. Long distance walking elicited positive emotions, reduced the effects of life-stress, and promoted an increased sense of well-being and personal growth. Results are aligned to theories and concepts from positive psychology

    Gamer Girls: Navigating a Subculture of Gender Inequality

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    Purpose Video gaming, which remains culturally embedded in masculine ideals, is increasingly becoming a leisure activity for female consumers. Guided by social dominance theory, this paper examines how female gamers navigate the masculine-oriented gaming consumption context. Methodology/approach Eight avid female gamers (ages 20–29) participated in-depth interviews, following a phenomenological approach to better understand their lived experiences with video gaming. Data were analyzed using phenomenological procedures. Findings Findings reveal an undercurrent of gender-based consumer vulnerability, driven by stereotypical perceptions of “gamer girls” in the masculine-oriented gaming subculture. Further, the findings highlight the multilayered, multidimensional nature of gaming as a vulnerable consumption environment, at individual, marketplace, and cultural levels. Social implications The culturally embedded gamer girl stereotype provides a foundation upon which characteristics of consumer vulnerability flourish, including a culture of gender-based consumer harassment, systematic disempowerment in the marketplace, and conflicting actions and attitudes toward future cultural change. Originality/value This research suggests female gamers struggle to gain a foothold in gaming due to the socially and culturally constructed masculine dominance of the field. Our research study provides a stepping-stone for future scholars to explore gendered subcultures and begins to address the dynamic interplay of power, gender, technology, and the market

    The role of sentinel node tumor burden in modeling the prognosis of melanoma patients with positive sentinel node biopsy: an Italian melanoma intergroup study (N = 2,086)

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    Background The management of melanoma patients with metastatic melanoma in the sentinel nodes (SN) is evolving based on the results of trials questioning the impact of completion lymph node dissection (CLND) and demonstrating the efficacy of new adjuvant treatments. In this landscape, new prognostic tools for fine risk stratification are eagerly sought to optimize the therapeutic path of these patients. Methods A retrospective cohort of 2,086 patients treated with CLND after a positive SN biopsy in thirteen Italian Melanoma Centers was reviewed. Overall survival (OS) was the outcome of interest; included independent variables were the following: age, gender, primary melanoma site, Breslow thickness, ulceration, sentinel node tumor burden (SNTB), number of positive SN, non-sentinel lymph nodes (NSN) status. Univariate and multivariate survival analyses were performed using the Cox proportional hazard regression model. Results The 3-year, 5-year and 10-year OS rates were 79%, 70% and 54%, respectively. At univariate analysis, all variables, except for primary melanoma body site, were found to be statistically significant prognostic factors. Multivariate Cox regression analysis indicated that older age (P < 0.0001), male gender (P = 0.04), increasing Breslow thickness (P < 0.0001), presence of ulceration (P = 0.004), SNTB size (P < 0.0001) and metastatic NSN (P < 0.0001) were independent negative predictors of OS. Conclusion The above results were utilized to build a nomogram in order to ease the practical implementation of our prognostic model, which might improve treatment personalization

    Mental Health of Long Term Survivors of Childhood and Young Adult Cancer

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    Background/Objectives Leukemic cells produce higher amounts of ROS than healthy cells and express low levels of antioxidant enzymes such as catalase (CAT) and superoxide dismutase (SOD). Recently, it was demonstrated that rMnSOD, a recombinant new isoform of MnSOD, recently isolated from human liposarcoma cell line, is able to trigger apoptosis of human T-ALL cells (99%) without toxic effects on healthy cells. The present study was aimed to verify if rMnSOD is able to induce apoptosis and to stop in G0/G1 stage of the cell cycle in pediatric patients with B-cell acute lymphoblastic leukaemia (ALL) and if it displays synergic action with daunorubicin. Design and Methods Cells were collected from three patients diagnosed for B-cell ALL at the Pediatric Oncology of University “Luigi Vanvitelli”. Cell viability, apoptosis and cell cycle of lymphoblasts and SUP-B15 cell line (ATCC) were analyzed through “ Muse Kit” after rMnSOD treatment. ROS analysis was detected with NAC. Apoptotic fragmentations of SUP-B15 were demonstrated by confocal imaging. Results We observed that low concentrations of rMnSOD are able to trigger apoptosis of SUP-B15 cell line and B-ALL cells from pediatric patients. In detail, we observed an apoptosis rate from 30% to 46% in B-ALL pediatric patient cells and of 45% in SUP-B15 cell line. Instead, cell cycle analysis showed a cell fraction decrease in G0/G1 phase. Moreover, the synergic activity of rMnSOD and Daunorubicin induces apoptosis in 92% of cells, by comparing the treatment with the single substances, rMnSOD (64,7%) and Daunorubicin (23,9%). Confocal microscopy analysis revealed internalization of rMnSOD in SUP-B15 cells and evident apoptotic alterations, such as nuclear fragmentations and apoptotic-bodies. In conclusion, rMnSOD exerts toxic activity only against cancer cells, by enhancing drug effect, thus allowing to utilize lower concentration of standard chemotherapy to increase the apoptosis level
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