Discrimination of freshwater fish species by Matrix-Assisted Laser Desorption/Ionization- Time Of Flight Mass Spectrometry (MALDI-TOF MS): a pilot study

In this study we discriminate three freshwater fish species (the shad Alosa agone Scopoli 1786, the whitefish Coregonus macrophthalmus N?sslin1882 and the roach Rutilus rutilus Linnaeus 1758) by Matrix-Assisted Laser Desorption/Ionization- Time Of Flight Mass Spectrometry (MALDI-TOF MS) using both muscle and liver tissues. The technology enables to analyze tissues after a simple single-step extraction procedure without any further purification. The molecular profile of muscle tissues showed the most intense peaks at m/z range of 11,354.0 (?2.0 SD) Da, 3508.5 (?1.5 SD) Da and 8567.2 (?1.1 SD) Da for the shad, the whitefish and the roach respectively. The molecular profiles of liver tissues exhibit most of the highest peak intensities in the range between 2000 and 6000 m/z values. The roach shows the clearest pattern with high intensities detected at mass ranges between 3000 and 3550 Da with maxima at m/z 3035.2 (?0.2) Da and 3468.7 (?0.3) Da. The shad shows a shared high peak at m/z 3429.0 (?0.3) Da. The whitefish shows a group of major peaks in the m/z range of 3000-3700 Da with the highest being at 3635 (?0.3) Da. The overall signal pattern generated is highly specific for each species and, according to cluster analyses based on the total number of peaks, we could discriminate the three species

An Introduction to the Project BLASCO - Blending LAboratory and Satellite techniques for detecting CyanObacteria

Algal blooms can have an impact on health care costs, on the costs associated with the treatment of water intended for human consumption and on the tourism industry. The implementation of early warning systems would reduce these costs and the efforts needed to face and control the harmful effects of an algal bloom. A system for monitoring the quality of the waters, which operates on a large scale and at high frequency, would allow to keep under control the evolution of a bloom. The observation by satellite allows such a monitoring: in particular, the project is focused on the development of techniques for the analysis of satellite images, in order to detect the specific phytoplankton species potentially responsible for bloom formation in lakes. To reach this goal, it is necessary to analyse the spectral response characteristic of cyanobacteria and to develop algorithms to be applied to the analysis of satellite images. New calibration algorithms for the interpretation of satellite images will be obtained in lab experiments, using algal cultures. The developed algorithms will be tested through the analysis of remote sensing images, with particular attention to the bloom events occurring in the lakes of Lombardy and Piedmont. Field data on water optical properties and phytoplankton samples will be also collected. Moreover, different approaches will be applied and compared to quantify the amount of cyanobacteria (HPLC, counting, in vivo fluorimetry, spectroradiometry). Among the main results there will be the creation of a dataset of spectral signatures of some cyanobacteria taxa, as well as the development of calibration curves for the qualitative and quantitative estimation of the blooms. In general, we expect that it will be possible to distinguish, in natural conditions, the spectral signatures of cyanobacteria, even at low concentrations and within mixed populations of phytoplankton

Cationic porphyrins are reversible proteasome inhibitors

The aim of this study is to verify if watersoluble porphyrins can be used as proteasome inhibitors. We have found that cationic porphyrins inhibit proteasome peptidase activities much more effectively than the corresponding anionic derivatives. The relevance of electrostatics in driving porphyin−proteasome interactions has been confirmed by the observation that the inhibitory efficiency of the cationic macrocycles decreases with the number of positive substituents. We have also investigated various metalloporphyrins, which differ due to the different propension of the central metal ion toward axial coordination. Our experimental results indicate that the naked cationic porphyrins are the most active in reversibly inhibiting the three main protease activities of the proteasome in the micromolar range. A spectroscopic characterization of porphyrin−proteasome interactions by UV−vis spectra parallels the results of inhibition assays: the higher the inhibitory effect the stronger the spectroscopic variations are. To interpret the action of porphyrins at a molecular level, we have performed calculations evidencing that cationic porphyrins may hinder the access to the canonical proteolytic site on the proteasome β5 subunit. In particular, an inspection of the top-scoring docking modes shows that the tetracationic porphyrin blocks the catalytic pocket, close to the N termini of the β5 proteasome subunit, more efficiently than its anionic counterpart. Proteasome inhibition activity of porphyrins unites their known anticancer properties making them suitable as a scaffold for the design of novel multitargeted molecules

Establishment of Corbicula fluminea (O.F. M?ller, 1774) in Lake Maggiore: a spatial approach to trace the invasion dynamics

We analysed the dynamics of the invasive Asian basket clam Corbicula fluminea in Lake Maggiore (Italy), recorded for the first time in August 2010. In order to reveal the extent of its dispersal, we monitored 30 locations along the lake for presence/absence of clams. This assessment of population structure, density and biomass is based on quantitative samples collected along the southern shoreline at four sites with diverse types of habitats. In the present study, the on-going process of Corbicula invasion was analysed from a spatial and temporal perspective. We compared density and size structure of the population among the sites (spatial distribution). We attempted to trace the colonization dynamics of the clams, so the invasion dynamics were tentatively reconstructed from spatial distribution of size /age groups and the contribution of the last recruited cohort to total population density along the lake littoral zone. Results from our surveys conducted in 2010-2011 have demonstrated that the Asian clam was well-established in the lake, thus about one-third of the lake (i.e. the southern basin) was already colonized by C. fluminea in 2011. Size frequency distribution in autumn 2011 further illustrated reproduction events and new recruitments. Population densities in Lake Maggiore were among the highest ever recorded in an Italian lake. Both the rapid spread of Corbicula in the littoral area and the relatively high densities, even at the most recently invaded sites, infer the potential ecosystem impacts associated with a dominant invasive species. Data reported here are not intended to be exhaustive since they concern only two years of investigations, so more detailed studies on both the ecology and invasive habits of this new alien species in Lake Maggiore are planned. The spatial approach used in the present study may clarify the dynamics of this invasion. Future monitoring might help us to disentangle the effects of spatial variability versus temporal succession during the establishment of the invasive species

Risultati del progetto SISTO

Not availableRisultati del progetto SIST

Interazione di porfirine idrosolubili con molecole di interesse biologico

Dottorato di ricerca in scienze chimiche. 11. ciclo. Tutore Roberto Purrello.Consiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

A simple method for rapid purification of phycobiliproteins from Arthrospira platensis and Porphyridium cruentum biomass

Membrane chromatography was exploited to purify allophycocyanin, phycocyanin and B-phycoerythrin from aqueous extracts of fresh or freeze-dried biomass of Arthrospira platensis (Cyanobacteria) and Porphyridium cruentum (Rhodophyta). The method can be tuned to obtain products having various degree of purity and avoids expensive and time consuming column chromatography and ultrafiltration steps. A commercial polyvinylidene fluoride (PVDF) microfiltration membrane (hydrophilic and low protein binding) was used as an ammonium sulphate responsive stationary phase to carry out the purification process. Analytical grade purity was achieved for phycocyanin (purity = 4.2–4.5, yield = 75–82 %) and B-phycoerythrin (purity = 4.5–4.8, yield = 69–71 %). Good purification, even if lower than analytical grade, was achieved for allophycocyanin (purity = 3.3–3.7, yield = 42–47%)

Chlorophyll a interference in phycocyanin and allophycocyanin spectrophotometric quantification

The accurate quantification of cyanobacteria phycobiliproteins is an important aspect in various research topics, such as cyanobacteria ecology and physiology studies, and especially to calibrate algorithms used in remote sensing of cyanobacterial blooms. Here we present a spectroscopic approach, exploiting spectrophotometric equations, aimed at improving the phycocyanin and allophycocyanin quantification when chlorophyll a is present in the phycobiliprotein aqueous extract

Purification of phycocyanin from Arthrospira platensis by hydrophobic interaction membrane chromatography

The cyanobacterium Arthrospira platensis is an important source of phycocyanin, which has many commercial applications in foods, cosmetics and pharmaceutics. In this study, hydrophobic interaction membrane chromatography (HIMC) was used for the first time to separate phycocyanin from allophycocyanin and obtain analytical grade phycocyanin, avoiding packed bed (i.e., packed column) chromatography steps. The extraction of phycobiliproteins was carried out on freeze-dried biomass samples suspended in NaCl 0.1 M, and the phycobiliprotein crude extract was obtained by centrifuging the suspension to eliminate cell debris. The crude extract, after the addition of an appropriate amount of ammonium sulphate, was loaded on an ammonium sulphate responsive commercial hydrophilic polyvinylidene fluoride (PVDF) membrane for the HIMC purification process. Applying a two-step HIMC purification procedure, a phycocyanin purity ratio of 4.20 and a yield of 67.0% was attained