Effect of ornithine decarboxylase and norspermidine in modulating cell division in the green alga Chlamydomonas reinhardtii

The extensive genetic resources of Chlamydomonas has led to its widespread use as a model system for understanding fundamental processes in plant cells, including rates of cell division potentially modulated through polyamines. Putrescine was the major polyamine in both free (88%) and membrane-bound fractions (93%) while norspermidine was the next most abundant in these fractions accounting for 11% and 6%, respectively. Low levels of diaminopropane, spermidine and spermine were also observed although no cadaverine or norspermine were detected. Ornithine decarboxylase (ODC, EC 4.1.1.17) activity was almost five times higher than arginine decarboxylase (ADC, EC 4.1.1.19) and is the major route of putrescine synthesis. The fluoride analogue of ornithine (α-DFMO) inhibited membrane associated ODC activity whilst simultaneously stimulating cell division in a dose dependent manner. Following exposure to α-DFMO the putrescine content in the cells declined while the norspermidine content increased over two fold. Addition of norspermidine to cultures stimulated cell division mimicking the effects observed using DFMO and also reversed the inhibitory effects of cyclohexylamine on growth. The results reveal that ODC is the major route to polyamine formation in the Chlamydomonas CC-406 cell-wall mutant, in contrast to the preferential ADC route reported for Chlorella vulgaris, suggesting that significant species differences exist in biosynthetic pathways which modulate endogenous polyamine levels in green algae

Floristic diversity in different urban ecological niches of a southern European city

The present paper aimed at studying the vertical and horizontal spatial distribution, species richness and diversity of vascular plants in different urban ecological niches (urban habitats) by means of the case study of Bologna (Italy), a typical densely populated southern European city. A total of 477 species were found in the study area of the historical city centre, 30% of which were alien species. Alien plant species were mainly present among phanerophytes, while native plants were mainly therophytes and hemicryptophytes. The habitats that mostly contributed to the species total richness were seminatural soils, followed by paved areas, walls, rooftops and manholes. The number of exclusive species decreased according to the selectiveness of the habitat, with manholes and rooftops being the most selective. The presence of hemicryptophytes constant decreased going from 27% of more humid habitats to 5% of more arid habitats, so that they can be considered a water availability biomarker. Urban habitat quality, measured by the number of native species, was directly proportional to the strength of selective factors and inversely proportional to the rate of disturbance, with roofs and seminatural soils having, respectively, the highest and lowest quality. Finally, a relation between species richness and street characteristics, like width, orientation and type of flooring, was demonstrated

Extraction Improvement and Chemometric Study

Funding Information: This work was supported by the NoAW project (‘‘Innovative approaches to turn agricultural waste into ecological and economic assets”), founded by the European Union Horizon 2020 research and innovation program under the grant agreement No 688338. This research was carried out within the Agritech National Research Center and received funding from the European Union Next-GenerationEU (PIANO NAZIONALE DI RIPRESA E RESILIENZA (PNRR)–MISSIONE 4 COMPONENTE 2, INVESTIMENTO 1.4–D.D. 1032 17/06/2022, CN00000022), Italy. This study was also funded by national funding by FCT, Foundation for Science and Technology, MCTES, and by ESF (European Social Fund) through NORTE 2020 (Programa Operacional Região Norte), Portugal, through the individual PhD research grant (SFRH/BD/146080/2019) of V.L. This work was also supported by the MEtRICs unit which is funded by national funds from FCT/MCTES (UIDB/04077/2020 and UIDP/04077/2020) and by the Associate Laboratory for Green Chemistry–LAQV which is financed by national funds from FCT/MCTES (UIDB/50006/2020 and UIDP/50006/2020). Publisher Copyright: © 2023 by the authors.In the last 20 years, an increased interest has been shown in the application of different types and combinations of enzymes to obtain phenolic extracts from grape pomace in order to maximize its valorization. Within this framework, the present study aims at improving the recovery of phenolic compounds from Merlot and Garganega pomace and at contributing to the scientific background of enzyme-assisted extraction. Five commercial cellulolytic enzymes were tested in different conditions. Phenolic compound extraction yields were analyzed via a Design of Experiments (DoE) methodology and a second extraction step with acetone was sequentially added. According to DoE, 2% w/w enzyme/substrate ratio was more effective than 1%, allowing a higher total phenol recovery, while the effect of incubation time (2 or 4 h) variation was more enzyme-dependent. Extracts were characterized via spectrophotometric and HPLC-DAD analyses. The results proved that enzymatic and acetone Merlot and Garganega pomace extracts were complex mixtures of compounds. The use of different cellulolytic enzymes led to different extract compositions, as demonstrated using PCA models. The enzyme effects were observed both in water enzymatic and in the subsequent acetone extracts, probably due to their specific grape cell wall degradation and leading to the recovery of different molecule arrays.publishersversionpublishe

Unexpected interfarm transmission dynamics during a highly pathogenic avian influenza epidemic

Next-generation sequencing technology is now being increasingly applied to study the within- and between-host population dynamics of viruses. However, information on avian influenza virus evolution and transmission during a naturally occurring epidemic is still limited. Here, we use deep-sequencing data obtained from clinical samples collected from five industrial holdings and a backyard farm infected during the 2013 highly pathogenic avian influenza (HPAI) H7N7 epidemic in Italy to unravel (i) the epidemic virus population diversity, (ii) the evolution of virus pathogenicity, and (iii) the pathways of viral transmission between different holdings and sheds. We show a high level of genetic diversity of the HPAI H7N7 viruses within a single farm as a consequence of separate bottlenecks and founder effects. In particular, we identified the cocirculation in the index case of two viral strains showing a different insertion at the hemagglutinin cleavage site, as well as nine nucleotide differences at the consensus level and 92 minority variants. To assess interfarm transmission, we combined epidemiological and genetic data and identified the index case as the major source of the virus, suggesting the spread of different viral haplotypes from the index farm to the other industrial holdings, probably at different time points. Our results revealed interfarm transmission dynamics that the epidemiological data alone could not unravel and demonstrated that delay in the disease detection and stamping out was the major cause of the emergence and the spread of the HPAI strain

Evaluation of the activity of natural phenolic antioxidants, extracted from industrial coffee residues, on the stability of poly(1,4‐butylene succinate) formulations

In this work, the evaluation of the antioxidant activity of natural phenolic compounds is performed and compared to that of a conventional antioxidative agent. Phenolic molecules, extracted from industrial processing coffee residues, are added to a matrix of poly(1,4-butylene succinate) (PBS). The apparent activation energy (Ea) of the thermo-oxidative degradation is calculated by employing different methods like Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa and Friedman. The results are compared with the antioxidant activity evaluation obtained through the ABTS radical scavenging assay. From the average activation energies, it is observed that the addition of the natural antioxidants led to an increase in the activation energy of the degradation process as a function of the phenolic compound content. This trend is confirmed by the results of the ABTS assay. Hence, this study proves that the active molecules extracted from agri-food waste could be employed to improve the antioxidant capacity of the biopolymer, even if the composition of the extract must be evaluated in order to mitigate the effects of other components

From winery waste to bioactive compounds and new polymeric biocomposites: a contribution to the circular economy concept

The paper aims at optimising and validating possible routes toward the full valorisation of grape agrowaste to produce bioactive molecules and new materials. Starting from Merlot red pomace, phenol complex mixtures were successfully extracted by using two different approaches. Extracts obtained by solvent-based (SE) technique contained up to 46.9 gGAeq/kgDW of total phenols. Depending on the used solvent, the prevalence of compounds belonging to different phenol families was achieved. Pressurized liquid extraction (PLE) gave higher total phenol yields (up to 79 gGAeq/kgDW) but a lower range of extracted compounds. All liquid extracts exerted strong antioxidant properties. Moreover, both SE and PLE extraction solid residues were directly exploited (between 5 and 20% w/w) to prepare biocomposite materials by direct mixing via an eco-friendly approach with PHBV polymer. The final composites showed mechanical characteristics similar to PHVB matrix. The use of pomace residues in biocomposites could therefore bring both to the reduction of the cost of the final material, as a lower amount of costly PHBV is used. The present research demonstrated the full valorisation of grape pomace, an agrowaste produced every year in large amounts and having a significant environmental impact

Monomers, Materials and Energy from Coffee By-Products: A Review

open11siIn recent years, the circular economy and sustainability have gained attention in the food industry aimed at recycling food industrial waste and residues. For example, several plant-based materials are nowadays used in packaging and biofuel production. Among them, by-products and waste from coffee processing constitute a largely available, low cost, good quality resource. Coffee production includes many steps, in which by-products are generated including coffee pulp, coffee husks, silver skin and spent coffee. This review aims to analyze the reasons why coffee waste can be considered as a valuable source in recycling strategies for the sustainable production of bio-based chemicals, materials and fuels. It addresses the most recent advances in monomer, polymer and plastic filler productions and applications based on the development of viable biorefinery technologies. The exploration of strategies to unlock the potential of this biomass for fuel productions is also revised. Coffee by-products valorization is a clear example of waste biorefinery. Future applications in areas such as biomedicine, food packaging and material technology should be taken into consideration. However, further efforts in techno-economic analysis and the assessment of the feasibility of valorization processes on an industrial scale are needed.openSisti, Laura; Celli, Annamaria; Totaro, Grazia; Cinelli, Patrizia; Signori, Francesca; Lazzeri, Andrea; Bikaki, Maria; Corvini, Philippe; Ferri, Maura; Tassoni, Annalisa; Navarini, LucianoSisti, Laura; Celli, Annamaria; Totaro, Grazia; Cinelli, Patrizia; Signori, Francesca; Lazzeri, Andrea; Bikaki, Maria; Corvini, Philippe; Ferri, Maura; Tassoni, Annalisa; Navarini, Lucian

Surface functionalization of extracellular vesicle nanoparticles with antibodies: a first study on the protein corona "variable"

To be profitably exploited in medicine, nanosized systems must be endowed with biocompatibility, targeting capability, the ability to evade the immune system, and resistance to clearance. Currently, biogenic nanoparticles, such as extracellular vesicles (EVs), are intensively investigated as the platform that naturally recapitulates these highly needed characteristics. EV native targeting properties and pharmacokinetics can be further augmented by decorating the EV surface with specific target ligands as antibodies. However, to date, studies dealing with the functionalization of the EV surface with proteins have never considered the protein corona "variable", namely the fact that extrinsic proteins may spontaneously adsorb on the EV surface, contributing to determine the surface, and in turn the biological identity of the EV. In this work, we explore and compare the two edge cases of EVs modified with the antibody Cetuximab (CTX) by chemisorption of CTX (through covalent binding via biorthogonal click-chemistry) and by formation of a physisorbed CTX corona. The results indicate that (i) no differences exist between the two formulations in terms of binding affinity imparted by molecular recognition of CTX versus its natural binding partner (epidermal growth factor receptor, EGFR), but (ii) significant differences emerge at the cellular level, where CTX-EVs prepared by click chemistry display superior binding and uptake toward target cells, very likely due to the higher robustness of the CTX anchorage