Biotechnological conversions of biodiesel derived waste glycerol by yeast and fungal species

Fifteen eukaryotic microorganisms were tested for their ability to assimilate biodiesel derived waste glycerol and convert it into value-added metabolic products. For this purpose yeast and Zygomycetes strains were cultivated in nitrogen-limited raw glycerol-based media (initial glycerol concentration 30 g/L). Yeasts tested accumulated restricted lipid quantities (up to ∼22%, wt/wt, in the case of Rhodotorula sp), while differentiations in their fatty acid composition were recorded in relation to the yeast strains employed and the fermentation time. On the contrary, fungi accumulated higher quantities of lipid inside their mycelia (ranging between 18.1 and 42.6%, wt/wt, of dry biomass) that contained in variable amounts the medically important GLA (γ-linolenic acid). Moreover, Yarrowia lipolytica, Pichia membranifaciens and Thamnidium elegans were further studied in media having increased initial glycerol concentrations. In these conditions Y. lipolytica secreted significant amounts of acetic acid (29.2 g/L), as well as mannitol (19.4 g/L) while P. membranifaciens reached 28.4 g/L of biomass at glycerol concentration 90 g/L. T. elegans produced 11.6 g/L of oil, with 71.1%, wt/wt, of fat in biomass, while the maximum concentration of GLA was 371 mg/L. Detailed analysis of T. elegans lipids indicated that the phospholipids fraction was particularly rich in polyunsaturated fatty acids.     

Engineering analysis of uncertainties in the performance evaluation of CHP systems

From January 1, 2011, in all UE countries the combined production of electric (or mechanical) and thermal energy (also called Combined Heat and Power, CHP, or cogeneration) is recognized as a high efficiency technology only when it is able to ensure a minimum value of energy saving with respect to the separate production of the same energy flows. The Directive 8/2004/EC, and a few successive Decisions of the European Commission, introduced a methodology to establish whether any cogeneration plant, existing or new, can be acknowledged as a high-efficiency CHP plant, and can therefore be supported from the UE member states. In the paper, such methodology, based on the evaluation of a standard Primary Energy Saving (PES) index, is briefly described, and then a metrological analysis is presented, in order to evaluate the uncertainties affecting the field evaluation of such index. Three numerical examples are also presented and discussed, referred to natural gas plants, showing that the evaluation of the PES index can be quite critical, especially for values close to the minimum limit fixed by the Directive, and in particular for small and medium scale CHP units, mainly due to the low accuracy that usually affect, in such cases, the measures of the fuel input.     

Is it possible to create an innovative craft durum wheat beer with sourdough yeasts? A case study

Craft beer is often produced as a non‐filtered, unpasteurized and bottle re‐fermented beer, whose production is aimed at maintaining original sensory characteristics. The intention of most micro‐breweries is to meet these requirements in producing a high‐quality beer. In Italy, as well as in Sardinia, the number of micro‐breweries is increasing. In an attempt to make this product more original, new strains of Saccharomyces cerevisiae were selected. Sourdough yeasts were used as an alternative source of starters for beer production. In this particular work, two wheat beers were compared, one brewed with an autochthonous yeast isolated from sourdough and the other brewed with a commercial yeast normally used in Italian micro‐breweries. The wheat beer fermented with the autochthonous yeast had the highest ethanol content, the lowest pH and the highest content of esters and alcohols. From a sensory point of view the two beers showed significant differences in the triangle test, but were not significantly different in the paired test with preference. Copyright © 2015 The Institute of Brewing & Distilling     

Analysis of pineapple [Ananas comosus (L.) Merr.] fruit proteinases by 2-D zymography and direct identification of the major zymographic spots by mass spectrometry

Cysteine proteinases present in pineapple plants are phytotherapeutical agents with anti-edematous, anti-inflammatory, anti-thrombotic and fibrinolytic activities. Active components involved have been only partially identified as bromelain, the major proteinase in pineapple fruits.     

Design and Characterization of a Peptide Mimotope of the HIV-1 gp120 Bridging Sheet

The Bridging Sheet domain of HIV-1 gp120 is highly conserved among the HIV-1 strains and allows HIV-1 binding to host cells via the HIV-1 coreceptors. Further, the bridging sheet domain is a major target to neutralize HIV-1 infection. We rationally designed four linear peptide epitopes that mimic the three-dimensional structure of bridging sheet by using molecular modeling. Chemically synthesized peptides BS3 and BS4 showed a fair degree of antigenicity when tested in ELISA with IgG purified from HIV(+) broadly neutralizing sera while the production of synthetic peptides BS1 and BS2 failed due to their high degree of hydrophobicity. To overcome this limitation, we linked all four BS peptides to the COOH-terminus of GST protein to test both their antigenicity and immunogenicity. Only the BS1 peptide showed good antigenicity; however, no envelope specific antibodies were elicited upon mice immunization. Therefore we performed further analyses by linking BS1 peptide to the NH2-terminus of the E2 scaffold from the Geobacillus Stearothermophylus PDH complex. The E2-BS1 fusion peptide showed good antigenic results, however only one immunized rabbit elicited good antibody titers towards both the monomeric and oligomeric viral envelope glycoprotein (Env). In addition, moderate neutralizing antibodies response was elicited against two HIV-1 clade B and one clade C primary isolates. These preliminary data validate the peptide mimotope approach as a promising tool to obtain an effective HIV-1 vaccine.     

Sex and Age-Related Differences in Neuroinflammation and Apoptosis in Balb/c Mice Retina Involve Resolvin D1

(1) Background: The pro-resolving lipid mediator Resolvin D1 (RvD1) has already shown protective effects in animal models of diabetic retinopathy. This study aimed to investigate the retinal levels of RvD1 in aged (24 months) and younger (3 months) Balb/c mice, along with the activation of macro- and microglia, apoptosis, and neuroinflammation. (2) Methods: Retinas from male and female mice were used for immunohistochemistry, immunofluorescence, transmission electron microscopy, Western blotting, and enzyme-linked immunosorbent assays. (3) Results: Endogenous retinal levels of RvD1 were reduced in aged mice. While RvD1 levels were similar in younger males and females, they were markedly decreased in aged males but less reduced in aged females. Both aged males and females showed a significant increase in retinal microglia activation compared to younger mice, with a more marked reactivity in aged males than in aged females. The same trend was shown by astrocyte activation, neuroinflammation, apoptosis, and nitrosative stress, in line with the microglia and Müller cell hypertrophy evidenced in aged retinas by electron microscopy. (4) Conclusions: Aged mice had sex-related differences in neuroinflammation and apoptosis and low retinal levels of endogenous RvD1.     

Numerical study of the optimization of the pitch angle of an alternative jet fan in a longitudinal tunnel ventilation system

This paper presents the results of a numerical investigation carried out on an alternative jet fan, noted in literature like Banana Jet Fan, equipped with inlet/outlet silencers inclined at a fixed pitch angle (α) inclined toward the tunnel floor.The aim of this paper is to optimize the pitch angle comparing the different ventilation performances, in terms of reduction of pressure losses and of energy saving, without vehicles and with traffic jam.The average velocity profile variation of the tunnel air jet around the outlet jet fan zone was evaluated with the numerical CFD analysis. This analysis showed that there exists an optimal pitch angle which minimizes the pressure losses, due to the flow attachment by varying the operative conditions (free tunnel and traffic jam).     

Quercetin Protects Human Thyroid Cells against Cadmium Toxicity

Various natural compounds have been successfully tested for preventing or counteracting the toxic effects of exposure to heavy metals. In this study, we analyzed the effects of cadmium chloride (CdCl₂) on immortalized, non-tumorigenic thyroid cells Nthy-ori-3-1. We investigated the molecular mechanism underlying its toxic action as well as the potential protective effect of quercetin against CdCl₂-induced damage. CdCl₂ suppressed cell growth in a dose- and time-dependent manner (IC50 value ~10 μM) associated with a decrease in levels of phospho-ERK. In addition, CdCl₂ elicited an increase in reactive oxygen species (ROS) production and lipid peroxidation. A significant increase in GRP78, an endoplasmic reticulum (ER) stress-related protein, was also observed. Supplementation of quercetin counteracted the growth-inhibiting action of CdCl₂ by recovering ERK protein phosphorylation levels, attenuating ROS overproduction, decreasing MDA content and reducing the expression of GRP78 in cells exposed to CdCl₂. Thus, in addition to revealing the molecular effects involved in cadmium-induced toxicity, the present study demonstrated, for the first time, a protective effect of quercetin against cadmium-induced damages to normal thyroid cells.     

Effect of hydrocarbon resin on the morphology and mechanical properties of isotactic polypropylene/clay composites

The article reports an investigation of the effect of a hydrocarbon resin, Necirés TR100, on the structure, morphology, and properties of two isotactic polypropylene/clay composites. The clays are Dellite HPS, a purified montmorillonite, and Dellite 67G, a purified and modified montmorillonite with a high content of quaternary ammonium salt. Necirés TR100 contains hydroxyl and acid groups, which were expected to interact during the melt mixing with the polar surface of the clays to have intercalation with Dellite HPS and/or exfoliation of Dellite 67G, which is already intercalated by the quaternary ammonium salt. The morphological results indicate that the composite isotactic polypropylene/Dellite HPS presents large and coarse clay domains, whereas the composite isotactic polypropylene/Dellite 67G presents a better distribution of the clay clusters, although the presence of some clay domains of a few μm are also detected. Although results from Wide Angle X‐ray Diffraction have indicated that Necirés TR100 has no effect on the layers distance of Dellite HPS and Dellite 67G its addition produces composites with clay particles homogenously distributed in the polyolefin matrix, better tensile properties (higher values of Young's modululs and elongation to break) and decrease of permeability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011