Isolation of biocrust cyanobacteria and evaluation of Cu, Pb, and Zn immobilisation potential for soil restoration and sustainable agriculture.

Soil contamination by heavy metals represents an important environmental and public health problem of global concern. Biocrust-forming cyanobacteria offer promise for heavy metal immobilisation in contaminated soils due to their unique characteristics, including their ability to grow in contaminated soils and produce exopolysaccharides (EPS). However, limited research has analysed the representativeness of cyanobacteria in metal-contaminated soils. Additionally, there is a lack of studies examining how cyanobacteria adaptation to specific environments can impact their metal-binding capacity. To address this research gap, we conducted a study analysing the bacterial communities of cyanobacteria-dominated biocrusts in a contaminated area from South Sardinia (Italy). Additionally, by using two distinct approaches, we isolated three Nostoc commune strains from cyanobacteria-dominated biocrust and we also evaluated their potential to immobilise heavy metals. The first isolation method involved acclimatizing biocrust samples in liquid medium while, in the second method, biocrust samples were directly seeded onto agar plates. The microbial community analysis revealed Cyanobacteria, Bacteroidota, Proteobacteria, and Actinobacteria as the predominant groups, with cyanobacteria representing between 13.3 % and 26.0 % of the total community. Despite belonging to the same species, these strains exhibited different growth rates (1.1-2.2 g L-1 of biomass) and capacities for EPS production (400-1786 mg L-1). The three strains demonstrated a notable ability for metal immobilisation, removing up to 88.9 % of Cu, 86.2 % of Pb, and 45.3 % of Zn from liquid medium. Cyanobacteria EPS production showed a strong correlation with the removal of Cu, indicating its role in facilitating metal immobilisation. Furthermore, differences in Pb immobilisation (40-86.2 %) suggest possible environmental adaptation mechanisms of the strains. This study highlights the promising application of N. commune strains for metal immobilisation in soils, offering a potential bioremediation tool to combat the adverse effects of soil contamination and promote environmental sustainability.

Microparticles from dental calculus disclose paleoenvironmental and palaeoecological records.

Plants have always represented a key element in landscape delineation. Indeed, plant diversity, whose distribution is influenced by geographic/climatic variability, has affected both environmental and human ecology. The present contribution represents a multi-proxy study focused on the detection of starch, pollen and non-pollen palynomorphs in ancient dental calculus collected from pre-historical individuals buried at La Sassa and Pila archaeological sites (Central Italy). The collected record suggested the potential use of plant taxa by the people living in Central Italy during the Copper-Middle Bronze Age and expanded the body of evidence reported by previous palynological and palaeoecological studies. The application of a microscopic approach provided information about domesticated crops and/or gathered wild plants and inferred considerations on ancient environments, water sources, and past health and diseases. Moreover, the research supplied data to define the natural resources (e.g., C4-plant intake) and the social use of the space during that period. Another important aspect was the finding of plant clues referable to woody habitats, characterised by broad-leaved deciduous taxa and generally indicative of a warm-temperate climate and grassy vegetation. Other unusual records (e.g., diatoms, brachysclereids) participated in defining the prehistoric ecological framework. Thus, this work provides an overview on the potential of the human dental calculus analysis to delineate some features of the ancient plant ecology and biodiversity.

Sustainability in Aquaponics: Industrial Spirulina Waste as a Biofertilizer for Lactuca sativa L. Plants.

Aquaponics represents an alternative to traditional soil cultivation. To solve the problem of nutrient depletion that occurs in this biotechnological system, the application of a spirulina-based biofertilizer was assessed. The microalgal waste used in this study came from industrial processing. Four different dilutions of the supernatant portion of this waste were sprayed on lettuce plants cultivated in an aquaponics system installed at the Botanical Gardens of the Tor Vergata University of Rome. The biofertilizer was characterized to evaluate its amount of macro- and micronutrients. The analysis conducted on the plants involved both morpho-biometric aspects and qualitative-quantitative measurements. The experiments showed that the spirulina extract had a positive effect on the growth and nutraceutical content of the lettuce plants; the obtained results highlighted that a dilution of 75% was the best for treatment. The use of the proposed organic and recycled fertilizer could increase the sustainability of crop cultivation and promote the functioning of aquaponics systems.

Pollen variability in Quercus L. species and relative systematic implications.

This study aims to address one of the challenges related to the complexity of the Quercus L. genus, that is the identification of structural elements favouring the systematic identification of the oak pollen. Thus, in this contribution, we explored the variation of morphometric and chemical parameters in pollen samples collected from 47 different Quercus species and hybrids. Several qualitative (e.g., outline in polar view, class, aperture structures) and quantitative (e.g., diameter, exine and sporoderm thickness, autofluorescence, content in proteins and plant metabolites) features were evaluated by optic microscopy and spectrophotometric assays. Statistical analyses were also carried out to assess significant correlations and clustering effects among the studied taxa, based on phenotypical and biochemical data, to identify the parameters which could be useful for taxonomic discrimination at inter- and intra-specific level. Only few morphological traits showed the potentiality to be diagnostic, such as pollen diameter and outline in polar view. The intensity of pollen autofluorescence varied among the samples but it did not seem to correlate with protein, carotenoid, phenolic and flavonoid content. However, differences in protein and carotenoid levels were detected, suggesting them as possible taxonomic discriminants for oak pollen. Thus, our work represents a step forward in understanding morphology and biochemistry of oak pollen, constitutes an experimental set-up applicable in future systematic studies on other genera, and opens new perspectives for further molecular investigations on Quercus species.

Influence of environmental conditions on the production of nutraceuticals in Italian edible plant landraces.

Autochthonous plant varieties, also referred to as landraces, represent an important genetic resource, being well-adapted to the environment in which they have been selected. Landraces usually show profiles rich in nutraceuticals, making them an effective and valuable alternative to commercial agri-products, as well as potential candidates for crop improvement programs. Basilicata region is recognized as an Italian hotspot for agrobiodiversity, due to its complex orography. Thus, this work aimed to characterize and monitor, for two successive years, the content of secondary metabolites and related antioxidant properties of seven different species, four officinal (i.e., wild fennel - Feoniculum vulgare Mill.; oregano - Origanum vulgare L.; thyme - Thymus vulgaris L.; valerian - Valeriana officinalis L.) and three fruit species (i.e., fig - Ficus carica L. cv. Dottato; sweet cherry Prunus avium L. cv. Majatica; plum - Prunus domestica L. cv. Cascavella Gialla), collected in three different sites of this region. In detail, spectrophotometric tests were performed to assess the concentration of phenolic compounds, flavonoids, and - for officinal plants - also terpenoids, together with the antiradical activity (FRAP assays). In addition, to better typify the phytocomplexes of these landraces, HPLC-DAD and GC-MS analyses were carried out. In general, officinal plants showed higher values of nutraceutical compounds and related bioactivity with respect to fruit species. The data showed how different accessions of the same species had different phytochemical profiles, according to the sampling area and the year of collection, suggesting a role for both genetic and environmental factors in determining the observed results. Therefore, the final goal of this research was also to find a possible correlation between environmental factors and nutraceutics. The greatest correlation was found in valerian, where a lower water intake seemed to lead to a higher accumulation of antioxidants, and in plum, where the flavonoid content correlated positively with high temperatures. All these outcomes contribute at valorising Basilicata landraces for their aptitude to be high-quality foods and, at the same time, promoting the preservation of the agrobiodiversity for this region.

Phytochemical and biological investigations on the pollen from industrial hemp male inflorescences.

Cannabis sativa L. belongs to the Cannabaceae family and includes annual, robust, fast-growing and generally dioecious plants. Industrial hemp, and particularly the inflorescences, has been recently recognized as important source of bioactive extracts with antioxidant and antimicrobial effects. The goal of the present study was to explore botanical, phytochemical, and biological properties of water and hydroalcoholic hemp pollen extracts from male inflorescences. The extracts from hemp pollen were found rich in phenolic compounds, such as hydroxytyrosol, coumaric acid, and hesperitin. The phenolic profile was also consistent with the observed scavenging/reducing, enzyme inhibitory, and antimicrobial properties of the extracts. Regarding the antimicrobial effects, Escherichia coli, Trycophyton rubrum, and T. tonsurans were the most sensitive to growth inhibitory effects (MIC values: 9.92-79.37 µg/mL) of the extracts. Whereas, null effects on prostate PC3 and myocyte C2C12 cell viability, in the range 1-1000 µg/mL, are consistent with MIC values and suggest extracts' biocompatibility. The experimental data obtained, which are not reflected in the literature as the topic of hemp pollen is almost completely unexplored, confirm the innovativeness of a product obtained directly from bees, which in the face of greater variability and complexity can reserve promising applications in food, pharmaceutical, and cosmetic sectors.

Phytochemicals and quality level of food plants grown in an aquaponics system.

BACKGROUND: Beyond nutrition, fruits and vegetables can be considered as natural sources of bioactive molecules, for which beneficial effects on human health are widely recognised. To improve food quality, soilless growing systems could represent a good strategy for promoting a sustainable food production chain, although the nutritional and nutraceutical properties of their products should be investigated in depth. The main quality traits and the volatile and non-volatile secondary metabolites of Solanum lycopersicum L., Petroselinum crispum (Mill.) Fuss and Ocimun basilicum L. grown in an aquaponics system and in organic farming were quantified and compared. RESULTS: On a fresh basis, soil-grown P. crispum and O. basilicum showed significantly higher total phenolics and antioxidant activity compared to aquaponic crops, whereas, on a dry basis, both plants showed opposite results. Soil-grown S. lycopersicum was significantly richer in total phenolics, whereas the aquaponic type showed a higher antioxidant activity. Aquaponics induced the accumulation of resveratrol in P. crispum, rosmarinic acid and myricetin in O. basilicum, and lycopene in S. lycopersicum. Among the volatile compounds, in O. basilicum, linalool was the main constituent in both treatments, whereas τ-cadinol represented the second constituent in aquaponic crops. The volatile profiles of P. crispum did not differ significantly between the two cultivation methods. CONCLUSION: The overall quality of organic and aquaponics cultures appeared to be comparable. The results showed that aquaponic farming method can be an innovative, rapid and sustainable way of producing quality food. © 2021 Society of Chemical Industry.

Exploiting the Potential in Water Cleanup from Metals and Nutrients of Desmodesmus sp. and Ampelodesmos mauritanicus.

Increasing levels of freshwater contaminants, mainly due to anthropogenic activities, have resulted in a great deal of interest in finding new eco-friendly, cost-effective and efficient methods for remediating polluted waters. The aim of this work was to assess the feasibility of using a green microalga Desmodesmus sp., a cyanobacterium Nostoc sp. and a hemicryptophyte Ampelodesmos mauritanicus to bioremediate a water polluted with an excess of nutrients (nitrogen and phosphorus) and heavy metals (copper and nickel). We immediately determined that Nostoc sp. was sensitive to metal toxicity, and thus Desmodesmus sp. was chosen for sequential tests with A. mauritanicus. First, A. mauritanicus plants were grown in the 'polluted' culture medium for seven days and were, then, substituted by Desmodesmus sp. for a further seven days (14 days in total). Heavy metals were shown to negatively affect both the growth rates and nutrient removal capacity. The sequential approach resulted in high metal removal rates in the single metal solutions up to 74% for Cu and 85% for Ni, while, in the bi-metal solutions, the removal rates were lower and showed a bias for Cu uptake. Single species controls showed better outcomes; however, further studies are necessary to investigate the behavior of new species.

Induction of Antioxidant Metabolites in Moringa oleifera Callus by Abiotic Stresses.

Moringa oleifeira has recently been subjected to numerous scientific studies pursuing its biological properties. However, biotechnological approaches promoting the synthesis of pharmacological compounds in this species are still scarce, despite the fact that moringa metabolites have shown significant nutraceutical effects. For this reason, in vitro cultures of moringa callus, obtained from leaf explantation, were subjected to various abiotic stresses such as temperature, salicylic acid, and NaCl, to identify the best growth conditions for the production of high levels of antioxidant molecules. Temperature stresses (exposure to 4 and 45 °C) led to no significant variation in moringa callus, in terms of antiradical metabolites, whereas salicylic acid (200 µM) and NaCl (50-100 µM) affected an increase of total phenolic compounds, after 15 and 30 days of treatment. Overall, the treatment with 100 µM NaCl for 30 days showed the highest free radical scavenging activity, comparable to that measured in moringa leaf. In addition, high doses of NaCl (200 µM) inhibited callus growth and reduced the amount and bioactivity of the secondary metabolites of callus. This study provides useful information to standardize growth conditions for the production of secondary metabolites in moringa in vitro cultures, a biotechnological system that could be employed for a rapid, controlled, and guaranteed production of antioxidant molecules for pharmaceutical purposes.

Antineoplastic activity of strawberry (Fragaria×ananassa Duch.) crude extracts on B16-F10 melanoma cells.

The antiproliferative and differentiation potential of anthocyanin-rich strawberry fruit crude extracts (SE) were investigated on B16-F10 murine melanoma cells. Treatment of melanoma cells with SE produced a remarkable reduction of cell proliferation, paralleled with both the lowering of the intracellular levels of polyamine, and the enhancement of tissue transglutaminase (TG2, EC 2.3.2.13) activity (used as a differentiation marker). To gain further insight into profiling altered protein expression as a potential biomarker of the SE action on melanoma cells, analysis of the proteomic profile was performed on the treated B16-F10 cells, compared to the control. Following SE treatment, 30 proteins resulted up-regulated, and 87 proteins were down-regulated. In particular proteins overexpressed in cancer cells, involved in tumor progression and metabolism, were down-regulated. The possibility that SE may affect the Warburg effect in B16-F10 melanoma cells is discussed.

Polyamine concentration, transglutaminase activity and changes in protein synthesis during cryopreservation of shoot tips of apple variety Annurca.

Changes in metabolism and protein expression were analysed during cryopreservation of the ancient apple variety Annurca. Our experiments concerned transglutaminase activity, polyamine levels and protein expression associated with shoot tip dehydration. Cryopreserved shoot tips displayed 72% regrowth after treatment in liquid medium with 0.75 M sucrose for 1 day followed by dehydration to 19% moisture content (fresh weight basis). After dehydration, the concentration of polyamines putrescine and spermidine decreased compared with untreated controls, while spermine concentration remained unaffected. Transglutaminase activity was slightly reduced in treated samples, while post-thaw regrowth enzyme activity approached control values. We also detected significant changes in protein expression profiles and identified six proteins related with stress response or involved in the slowing down of the cell cycle. The relationship between biochemical parameters, protein synthesis and cryotolerance is discussed.

Loading silica with metals (palladium or platinum) under mild conditions by using well-defined molecular precursors.

The loading of pre-treated amorphous silica with platinum or palladium was carried out by using the molecular precursors Pt2(micro-Cl)2Cl2(CO)2, or Pd2(micro-Cl)2Cl2(CO)2, respectively, which contain the required amount of coordinated CO to carry out the formation of the metal particles upon contact with moisture. The reactivity of the well-soluble mononuclear platinum complex cis-PtCl2(CO)2 with stoichiometric amounts of water was investigated either under N2 or CO. The metal nanoparticles produced on the silica matrix have been characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The catalytic performance of the silica-supported metals thus produced was evaluated in the hydrogenation of cyclohexene.