271 research outputs found
Development of Hybrid Titanium Oxide-based Systems for the Surface Stabilization of Reactive Oxygen Radicals
Biotechnological synthesis of succinic acid by actinobacillus succinogenes by exploitation of lignocellulosic biomass
Succinic acid is increasingly used in pharmaceutical industries, for the production of additives in food
industries, in agriculture and in refinery processes as a precursor of many chemical compounds among which
the most important is the succinate salt. It is also used as an ion chelator and surfactant, and for the
biochemicals production. Currently, succinic acid is mainly produced through chemical petroleum-based
processes, usually from n-butane using maleic anhydride. However, the use of petrochemical feedstocks
raises serious environmental problems, due to the higher values of temperature and pressure required. The
biotechnological production of succinic acid by microbial conversion of lignocellulosic biomass is attracting
growing interest due to the environmental and economic advantages offered.
This research is focused on the exploitation of Arundo donax (Giant reed) as a source of lignocellulosic
biomass. Arundo donax is a perennial crop particularly suitable for energy production, as it offers high yields
per hectare, even in partially fertile or polluted soils, not used for agriculture. Hydrolyzate of Arundo donax will
be used as growth media for the Actinobacillus succinogenes 130Z, a bacterium typically found in the bovine
rumen, that is recognized as one of the most promising for the biotechnological production of succinic acid, as
it is able to produce higher concentrations of succinic acid. The experimental analysis is carried out to
optimize the production of succinic acid taking into account the effect of the most critical parameters of the
process (microbial biomass, pH, reducing sugars, volatile fatty acids, and succinic acid). Tests have shown
that in 48h the sugars are completely biodegraded with a total production of bio-succinic acid of 5.9 g for 9.1 g
of reducing sugars, an hourly production 0.12 g h-1 with a yield equal to 65%
Application of Electroporation Technique in Biofuel Processing
Biofuels production is mostly oriented with fermentation process, which requires fermentable sugar as nutrient for microbial growth. Lignocellulosic biomass (LCB) represents the most attractive, low-cost feedstock for biofuel production, it is now arousing great interest. The cellulose that is embedded in the lignin matrix has an insoluble, highly-crystalline structure, so it is difficult to hydrolyze into fermentable sugar or cell protein. On the other hand, microbial lipid has been studying as substitute
of plant oils or animal fat to produce biodiesel. It is still a great challenge to extract maximum lipid from
microbial cells (yeast, fungi, algae) investing minimum energy. Electroporation (EP) of LCB results a significant increase in cell conductivity and permeability caused due to the application of an external electric field. EP is required to alter the size and structure of the biomass, to reduce the cellulose crystallinity, and increase their porosity as well as chemical composition, so that the hydrolysis of the carbohydrate fraction to monomeric sugars can be achieved rapidly and with greater yields. Furthermore, EP has a great potential to disrupt the microbial cell walls within few seconds to bring out the intracellular materials (lipid) to the solution. Therefore, this study aims to describe the challenges and prospect of
application of EP technique in biofuels processing
Biochar addition in the anaerobic digestion of the organic fraction of municipal solid waste for biogas production
The continuous decline of fossil fuel availability and the ever increasing concern about environmental pollution, expressed by scientists, governments and public at large, are stimulating the research on renewable energy production. In this perspective, anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW) is recently meeting with increasing interest. It is a process viable both from an economic and technological standpoints, capable to combine the environmental friendly re-cycle of large amount of OFMSW combined to the production of methane, an excellent fossil-based fuels substitute (Chatterjee and Mazumder, 2016).
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Microbial lipid extraction from Lipomyces starkeyi using irreversible electroporation
The aim of the study was to investigate the feasibility of using irreversible electroporation (EP) as a
microbial cell disruption technique to extract intracellular lipid within short time and in an eco-friendly
manner. An EP circuit was designed and fabricated to obtain 4 kV with frequency of 100 Hz of
square waves. The yeast cells of Lipomyces starkeyi (L. starkeyi) were treated by EP for 2-10 min
where the distance between electrodes was maintained at 2, 4, and 6 cm. Colony forming units
(CFU) were counted to observe the cell viability under the high voltage electric field. The forces of
the pulsing electric field caused significant damage to the cell wall of L. starkeyi and the disruption of
microbial cells was visualized by field emission scanning electron microscopic (FESEM) image. After
breaking the cell wall, lipid was extracted and measured to assess the efficiency of EP over other
techniques. The extent of cell inactivation was up to 95% when the electrodes were placed at the
distance of 2 cm, which provided high treatment intensity (36.7 kWh m ). At this condition,
maximum lipid (63 mg g ) was extracted when the biomass was treated for 10 min. During the
comparison, EP could extract 31.88% lipid while the amount was 11.89% for ultrasonic and 16.8%
for Fenton's reagent. The results recommend that the EP is a promising technique for lowering the
time and solvent usage for lipid extraction from microbial biomass. © 2018 American Institute of
Chemical Engineers Biotechnol
FXS-Like Phenotype in Two Unrelated Patients Carrying a Methylated Premutation of the FMR1 Gene
Fragile X syndrome (FXS) is mostly caused by two distinct events that occur in the FMR1 gene (Xq27.3): an expansion above 200 repeats of a CGG triplet located in the 5′UTR of the gene, and methylation of the cytosines located in the CpG islands upstream of the CGG repeats. Here, we describe two unrelated families with one FXS child and another sibling presenting mild intellectual disability and behavioral features evocative of FXS. Genetic characterization of the undiagnosed sibling revealed mosaicism in both the CGG expansion size and the methylation levels in the different tissues analyzed. This report shows that in the same family, two siblings carrying different CGG repeats, one in the full-mutation range and the other in the premutation range, present methylation mosaicism and consequent decreased FMRP production leading to FXS and FXS-like features, respectively. Decreased FMRP levels, more than the number of repeats seem to correlate with the severity of FXS clinical phenotypes
On the Emergy accounting for the evaluation of road transport systems: an Italian case study
Road transportation is one of the most polluting as well as energy-intensive sectors, and requires planning policies capable to address at the same time several different environmental, social, and economic issues. Cost-benefit analyses are generally carried out with a major focus on fuelling and driving efficiency, whereas a systemic approach appears to be needed for a more comprehensive evaluation of the alternatives that may become available to address any issue, be it intended for either short-term or long-term spans. For instance, building up a new infrastructure might allow for savings in time or fuel per km, but this may require an equivalent or even higher socio-environmental investment. In this work, a short review is presented of some systemic studies on transportation that use the emergy synthesis methodology. A case study is also addressed, concerning recent important expansion works on the Apennine Mountains section of the Italian major highway A1. In particular, the analysis points out the role of time saving, since for a new or renewed transport infrastructure (and when comparing for example road to rail transport) saved time is likely to become crucial in justifying civil enterprises. Nevertheless, the present emergy synthesis and the teaching of H.T. Odum (Odum & Odum, 2001) warn us that such “luxury” highly depends on the abundance of available energy, which is less and less given for granted, whereas a systemic analysis approach may indicate different levels of criticality when oriented towards environmental and well-being issues
Sphingolipid metabolic flow controls phosphoinositide turnover at the trans Golgi network
Sphingolipids are membrane lipids, which are globally required for eukaryotic life.
Sphingolipid composition varies among endomembranes with pre- and post-Golgi
compartments being poor and rich in sphingolipids, respectively. Thanks to this different
sphingolipid content, pre- and post-Golgi membranes serve different cellular functions.
Nevertheless, how subcellular sphingolipid levels are maintained in spite of trafficking and
metabolic fluxes is only partially understood. Here we describe a homeostatic control
circuit that controls sphingolipid levels at the trans Golgi network. Specifically, we show
that sphingomyelin production at the trans Golgi network triggers a signalling reaction
leading to PtdIns(4)P dephosphorylation. Since PtdIns(4)P is required for cholesterol, and
sphingolipid transport to the trans Golgi network, PtdIns(4)P consumption leads to the
interruption of this transport in response to excessive sphingomyelin production. Based on
this evidence we envisage a model where this homeostatic circuit maintains the lipid
composition of trans Golgi network and thus of post-Golgi compartments constant, against
instant fluctuations in the sphingolipid biosynthetic flow.Peer ReviewedPostprint (author's final draft
Is robotic right colectomy economically sustainable? A multicentre retrospective comparative study and cost analysis
Background
Following the Food and Drug Administration approval, robot-assisted colorectal surgery has gained more acceptance among surgeons. One of the open issues about robotic surgery is the economic sustainability. The aim of our study is to evaluate the economic sustainability of robotic as compared to laparoscopic right colectomy for the Italian National Health System.
Methods
We performed a retrospective multicentre case-matched study including 94 patients for each group from four different Italian surgical departments. An economic evaluation gathered from a real-world data was performed to assess the sustainability of the robotic approach for right colectomy in the Italian National Health System. In particular, a differential cost analysis between the two procedures was performed.
Results
No statistical differences were found between the two groups for postoperative outcomes. After a careful review of the literature on the cost assessment for the operative room, medical devices and hospital stay according with our data, we estimated the followings: (a) the mean operative room cost for robotic group was 2179 ± 476 € vs. 1376 ± 322 € for laparoscopic group; (b) the mean hospital stay cost for robotic group was 3143 ± 1435 € vs. 3292 ± 1123 € for laparoscopic group; and (c) the mean cost for instruments was 6280 € for robotic group vs. 1504 € for laparoscopic group. The total mean cost of robotic right colectomy was 11,576 ± 1915 € vs. 6196 ± 1444 € for laparoscopic right colectomy.
Conclusion
In conclusion, to date, robotic right colectomy with intracorporeal anastomosis does not provide any significant clinical advantages, which may justify the additional costs, as compared to its laparoscopic counterpart. Further evolution of robotic technology and experience may lead to a reduction of costs, especially if the robotic platform is used in an appropriate healthcare setting
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