38 research outputs found
Biotechnological potential of microalgae: morpho-physiological and biochemical studies
However, after 7 days, glucose-grown cells entered the stationary phase and started to accumulate lipids. Conversely, in cells grown in presence of AWP lipid accumulation was induced after 21 days of growth. In a second moment, to promote a more rapid lipid accumulation, cells grown in AWP and in normal autotrophic medium for 7 days were transferred under nutrient depletion. Both samples suddenly reached the stationary phase. Moreover, a decrease in pigment content, alteration of the cell morphology and concomitant lipid synthesis were observed. This study confirmed that glucose can be considered a very suitable substrate for the obtainment of high-lipid enriched N. oleoabundans. However, it is considered a very-expensive substrate. Then, N. oleoabundans growth can be alternatively coupled in a bioremediation process to obtain high biomass concentrations enriched in lipids.
This Thesis provides also advanced insights in the organization of the thylakoid protein complexes which characterize the photosynthetic membranes when N. oleoabundans is grown mixotrophically. Indeed, very little is known about this topic, but investigation in mechanisms which regulate photosynthetic light reactions and carbohydrate metabolisms might be useful for the scaling up of mixotrophic microalgal cultivation, for instance to plan the most fruitful type of illumination. In order to better understand the effects of mixotrophy on the organization of the thylakoid protein complexes which characterize the photosynthetic apparatus, thylakoids from cells of N. oleoabundans grown in presence of glucose were isolated to perform biochemical and biophysical analyses. On the whole, the results obtained showed dramatic changes in PSII activity and linear electron flow in mixotrophic samples with respect to autotrophic controls, with probable modifications in state-transition capability and reduced photosynthetic performance. However, further investigation are needed to provide a complete background. For this reason, this work can be considered a starting point from which further research might be developed.
Finally, in a third part the effects of the expression of two exogenous phytoene synthase from Arabidopsis thaliana (AtPSY) and Oryza sativa (OsPSY1) genes in the green microalga Chlamydomonas reinhardtii have been studied, with particular regard to carotenoid (Car) accumulation, Car profile changes and photosynthetic performance. The expression of the transgenes was confirmed in only one transformant with AtPSY, which showed increased amounts of Car. However, by further experiments in which cells were grown in different light regimes, it was shown that Car accumulation was light-dependent, while initial increased amounts of zeaxanthin, antheraxanthin, violaxanthin and lutein, were always observed in transformed cells. This altered Car profile caused a different use of the light during photosynthesis. In order to optimize exogenous Car production in microalgae like C. reinhardtii, basic knowledge of the Car biosynthetic pathway and its regulation needs to be improved. However, this work allowed to gain important knowledge on the genetic engineering of microalgal cells and the methods used might as well be applied to the fatty acid metabolic pathway for the increase in lipid accumulation in a very next future
The role of imaging in the diagnosis of recurrence of primary seminal vesicle adenocarcinoma
Primary seminal vesicle (SV) adenocarcinoma is a rare tumor. A small amount of data about the role of imaging to detect tumor recurrence is available. We report the case of a 58-year-old patient with primary SV clear-cell well-differentiated adenocarcinoma. Clinical and instrumental examinations were negative for the 32 months after treatments when computed tomography scan, [(18)F]fluoro-D-glucose positron emission tomography/computed tomography and pelvic magnetic resonance imaging showed the appearance of a lesion in the left perineal muscle suspected for recurrence. Patient was symptomless. Cytology of the suspected lesion confirmed SV adenocarcinoma recurrence. The combined approach, using radiological and nuclear medicine techniques, seems to be effective in the follow-up of SV adenocarcinoma. Technological advances, together with awareness of this rare tumor, have the potential of improving patients outcomes not only by providing earlier detection and accurate staging, but also by detecting recurrence and thereby avoiding delays and therapeutic dilemmas
Ecosystem-Based MSP for Enhanced Fisheries Sustainability: An Example from the Northern Adriatic (Chioggia\u2014Venice and Rovigo, Italy)
Human pressures on marine ecosystems significantly increased during last decades. Among the intense anthropic activities, industrial fisheries have caused the alteration of habitats, the reduction of biodiversity and the main fish stocks. The aim of this research, carried out in the Adriatic Sea, was to test a repeatable Marine Spatial Planning framework aimed at enhancing fisheries sustainability through the application of Decision Support Tools and the composition of a catalog of possible measures. The use of these tools proved very useful to identify possible criticalities and facilitate an effective exchange with fisheries stakeholders, local authorities, and fishermen, whose involvement was an indispensable step in the process. Tool-based analyses allowed to assess the spatial footprint of a range of anthropogenic pressures from human activities (e.g., fisheries, maritime traffic, and aquaculture). Within this multi-pressure scenario, special attention was paid to fishing-related disturbances and potential conflicts across different fishing m\ue9tier and with other sectors. Specifically, results highlighted the spatial features of the major fishing pressures (e.g., abrasion from trawling) affecting essential fish habitats, marine mammals and turtles in the study area. A portfolio of possible management measures is identified for the study area. It provides clear evidence that, in order to mitigate emerging conflicts and cumulative impacts, it is necessary to combine and integrate different types of measures: spatial measures modulated over time, monitoring and control, actions to fill knowledge gaps, concertation\u2014involvement\u2014co-management actions, improvement of governance systems, actions to support innovation in the sector, etc. Given the complex set of measures discussed, this work can provide a useful contribution to the management of fisheries both at local and regional level, fostering the transition to sustainable fisheries
How future surgery will benefit from SARS-COV-2-related measures: a SPIGC survey conveying the perspective of Italian surgeons
COVID-19 negatively affected surgical activity, but the potential benefits resulting from adopted measures remain unclear. The aim of this study was to evaluate the change in surgical activity and potential benefit from COVID-19 measures in perspective of Italian surgeons on behalf of SPIGC. A nationwide online survey on surgical practice before, during, and after COVID-19 pandemic was conducted in March-April 2022 (NCT:05323851). Effects of COVID-19 hospital-related measures on surgical patients' management and personal professional development across surgical specialties were explored. Data on demographics, pre-operative/peri-operative/post-operative management, and professional development were collected. Outcomes were matched with the corresponding volume. Four hundred and seventy-three respondents were included in final analysis across 14 surgical specialties. Since SARS-CoV-2 pandemic, application of telematic consultations (4.1% vs. 21.6%; p < 0.0001) and diagnostic evaluations (16.4% vs. 42.2%; p < 0.0001) increased. Elective surgical activities significantly reduced and surgeons opted more frequently for conservative management with a possible indication for elective (26.3% vs. 35.7%; p < 0.0001) or urgent (20.4% vs. 38.5%; p < 0.0001) surgery. All new COVID-related measures are perceived to be maintained in the future. Surgeons' personal education online increased from 12.6% (pre-COVID) to 86.6% (post-COVID; p < 0.0001). Online educational activities are considered a beneficial effect from COVID pandemic (56.4%). COVID-19 had a great impact on surgical specialties, with significant reduction of operation volume. However, some forced changes turned out to be benefits. Isolation measures pushed the use of telemedicine and telemetric devices for outpatient practice and favored communication for educational purposes and surgeon-patient/family communication. From the Italian surgeons' perspective, COVID-related measures will continue to influence future surgical clinical practice
In pea stipules a functional photosynthetic electron flow occurs despite a reduced dynamicity of LHCII association with photosystems
The flexible association of the light harvesting complex II (LHCII) to photosystem (PS) I and PSII to balance their excitation is a major short-term acclimation process of the thylakoid membrane, together with the thermal dissipation of excess absorbed energy, reflected in non-photochemical quenching of chlorophyll fluorescence (NPQ). In Pisum sativum, the leaf includes two main photosynthetic parts, the basal stipules and the leaflets. Since the stipules are less efficient in carbon fixation than leaflets, the adjustments of the thylakoid system, which safeguard the photosynthetic membrane against photodamage, were analysed. As compared to leaflets, the stipules experienced a decay in PSII photochemical activity. The supramolecular organization of photosystems in stipules showed a more conspicuous accumulation of large PSII-LHCII supercomplexes in the grana, but also a tendency to retain the PSI-LHCI-LHCII state transition complex and the PSI-LHCI-PSII-LHCII megacomplexes probably located at the interface between appressed and stroma-exposed membranes. As a consequence, stipules had a lower capacity to perform state transitions and the overall thylakoid architecture was less structurally flexible and ordered than in leaflets. Yet, stipules proved to be quite efficient in regulating the redox state of the electron transport chain and more capable of inducing NPQ than leaflets. It is proposed that, in spite of a relatively static thylakoid arrangement, LHCII interaction with both photosystems in megacomplexes can contribute to a regulated electron flow
Functionalisation of ceramic tile surface by soluble salts addition: part II. Titanium and Silver addition
The aim of this study was to assess surface functionalization of industrial ceramic tiles through the addition of soluble salts to improve mechanicalproperties (scratch and wear resistance) and conductivity, while preserving the aesthetic aspects of the finished product. This objective was pursuedthrough the application of different solutions of titanium and silver with a potential for transformation into titania and silver nanoparticles during thesintering of the material. The solutions, in different concentrations, were applied (300 g/m2) to unglazed green tiles by air brushing. The resultingproducts were polished and characterized in terms of microstructural, surface micromechanical, and technological properties based on the UNIEN ISO reference standards. The electrical conductivity deriving from the presence of titania and silver was also established with specific tests.The results were found to correlate with the results obtained from the addition of zirconium solutions as reported in part I of the paper
Enhanced photosynthetic linear electron flow in mixotrophic green microalga Ettlia oleoabundans UTEX 1185
Basic understanding of the photosynthetic physiology of the oleaginous green microalga Ettlia oleoabundans is still very limited, including the modulation of the photosynthetic membrane upon metabolism conversion from autotrophy to mixotrophy. It was previously reported that, upon glucose supply in the culture medium, E. oleoabundans preserves photosystem II (PSII) from degradation by virtue of a higher packing of thylakoid complexes. In this work, it was investigated whether in the mixotrophic exponential growth phase the PSII activity is merely preserved or even enhanced. Modulated fluorescence parameters were then recorded under short-term treatments with increasing irradiance values of white light. It was found that the mixotrophic microalga down-regulated the chlororespiratory electron recycling from photosystem I (PSI), but enhanced the linear electron flow from PSII to PSI. Ability to keep PSII more open than in autotrophic growth conditions indicated that the respiration of the glucose taken up from the medium fed the carbon fixing reactions with CO2. The overall electron poise was indeed well regulated, with a lesser need for thermal dissipation of excess absorbed energy. It is proposed that the significant, though small, increase in PSII maximum quantum yield in mixotrophic cells just reflects an improved light energy use and an increased photochemical capacity as compared to the autotrophic cells
A plant and a method for abating the amount of nitrogen of an organic waste from zootechnical farming
A plant is described for the abatement of the nitrogen load of organic waste of zootechnical farming, along with its relative method. The plant comprises a combination of at least one extraction and mixing tank, at least one dilution tank and at least one culture tank, connected in series and cascade. The tank contains a suspension culture of one or more native strains of microalgae previously isolated from the organic waste to be treated