Effect of selenium enrichment on metabolism of tomato (Solanum lycopersicum) fruit during post‐harvest ripening

BACKGROUND Selenium (Se) enrichment of plants seems effective in enhancing the health‐related properties of produce, and in delaying plant senescence and fruit ripening. The current study investigated the effects of Se on tomato fruit ripening. Tomato (Solanum lycopersicum L.) plants were grown in hydroponics with different Se‐enriched nutrient solutions. Se, as sodium selenate, was added at rate of 0 mg L‐1 (control), 1 mg L‐1, and 1.5 mg L‐1. RESULTS Selenium was absorbed by roots and translocated to leaves and fruit. Se enrichment did not significantly affect the qualitative parameters of fruit at commercial harvest, instead it delayed ripening by affecting specific ripening‐related processes (respiration, ethylene production, color evolution) during postharvest. In the current experiment 100 g of tomato hydroponically grown with a 1.5 mg Se L‐1 enriched solution provided a total of 23.7 μg Se. Selenium recommended daily intake is 60 μg for women and 70 μg for men, thus the daily consumption of 100 g of enriched tomato would not lead to Se toxicity, but would provide a good Se diet supplementation. CONCLUSIONS The cultivation of tomato plants in a Se‐enriched solution appeared effective in producing tomato fruit with improved performances during storage and postharvest shelf life, and also with greater potential health‐promoting properties

Ammonium thiosulphate assisted phytoextraction of mercury and arsenic in multi-polluted industrial soil

The possibility of using ammonium thiosulphate in assisted phytoextraction was evaluated on a greenhouse scale (mesocosm) for the simultaneous removal of mercury and arsenic from multi-polluted industrial soil. The addition of thiosulphate to the soil greatly promoted the uptake and translocation of both contaminants in the aerial parts of Brassica juncea and Lupinus albus. Thiosulphate showed great potential since it is a common fertilizer used to promote plant growth and is able to promote plant uptake of both Hg and As. Hg concentration in the aerial part of the plants reached 867 mg kg-1 in B. juncea and 114 mg kg-1 in L. albus. In the aerial parts, As concentration was about 9 mg kg-1 in B. juncea and 20 mg kg-1 in L. albus. This thus increases the applicability of phytoextraction in terms of cost and time especially if the remedial targets are based on bioavailable metal concentrations

The composting process from a waste management method to a remediation procedure

Composting is a controlled technology to enhance the natural aerobic process of organic wastes degradation. The resulting product is a humified material that is principally recyclable for agricultural purpose. The composting process is one of the most important tools for waste management, by the European Community legislation. In recent years composting has been increasingly used as a remediation technology to remove biodegradable contaminants from soil, and to modulate heavy metals bioavailability in phytoremediation strategies. An optimization in the recovery of resources from wastes through composting could enhance soil fertility and promote its use in the remediation biotechnologies of contaminated soils

De-inked paper sludge and mature compost as high-valuecomponents of soilless substrate to support tree growth

The recycled paper industry produces tons of waste whose disposal is a cost for industry and the environment. This research examines the suitability of de-inked paper sludge (DPS), after pelletization, as a sustainable alternative component to a peat-based growing media, creating ideal root conditions for tree development (e.g. high water storage, low compaction). DPS, tested on Lepidium sativum L. germination, did not show toxicity effects. Three species, Quercus ilex L., Lagerstroemia indica L. and Prunus serrulata “Kanzan”, were planted in 40 cm Ø pots filled with a control (peat, pumice and zeolite) and the experimental substrate (compost, DPS pellets, pumice and zeolite). After two years in the nursery, the trees were planted in situ. The physical and chemical properties of substrates were analyzed. Plant morphological and physiological parameters were monitored: trunk diameter, leaf dry matter, leaf nitrogen, chlorophyll, and photosynthetic efficiency. The new substrate showed higher Corg (+135%), total N (+73%) and easily available water (+19%), compared to the control substrate used in the nursery. In this new substrate, the trees showed similar radial growth values to the control in the nursery and after transplanting in situ improved their photosynthetic performance in terms of quantum yield of photosystem II (+36%, and +29% in P. serrulata and L. indica, respectively) and electron transport rate (+39%, +25%, and +32% in P. serrulata, Q. ilex and L. indica, respectively). Pelletization represents an attractive amendment for growing media, which enhances the plant’s physiological health status. This study proposes alternative recovery methods for paper industry waste with low environmental impact. As the process is developed locally, it should also contribute to reducing energy-related CO2 emissions from transport. Pelletization represents an attractive novelty in the use of DPS as amendment for growing media, which enhances the plant’s physiological health status. This study proposes alternative recovery methods for paper industry waste with low environmental impact. As the process is developed locally, it should also contribute to reducing energy-related CO2 emissions from transport

Efficacy and Comparison of Different Strategies for Selenium Biofortification of Tomatoes

At appropriate concentrations, selenium (Se) is beneficial for humans. Tomato appears to be one of the best commodities for producing Se-biofortified fruit for dietary supplementation. To assess the efficacy of different enrichment protocols, a total of four on-plant and off-plant trials were conducted. Hydroponically grown tomato plants were sprayed with: (i) chemically synthesized Se nanoparticles (SeNPs) at 0, 1, and 1.5 mg Se L−1 at blooming; (ii) sodium selenate (Na2SeO4) or SeNPs solution at 0, 5, and 10 mg Se L−1 when the fruit entered the immature green stage. With regard to the off-plant trials, harvested mature green fruit were immersed in Na2SeO4 solution: (iii) at 0, 5, 10, and 20 mg Se L−1 for 15 s under a vacuum; (iv) at 0, 40, and 80 mg Se L−1 for 1 h. Spraying Na2SeO4 induced higher Se accumulation in plant tissue than SeNPs: both protocols were effective in enriching tomatoes. Postharvest Se enrichment via vacuum infiltration caused textural damage, whereas passive immersion in solution induced fruit Se accumulation without causing any damage. SeNPs appear to be quantitatively less effective than Na2SeO4, but might be environmentally safer. Elemental Se carried by NPs may be more easily incorporated into organic forms, which are more bioavailable for humans. Passive immersion may represent an alternative Se-enrichment strategy, allowing for the biofortification of harvested tomato fruit directly, with lower risks of environmental pollution

Soil Remediation: Towards a Resilient and Adaptive Approach to Deal with the Ever-Changing Environmental Challenges

Pollution from numerous contaminants due to many anthropogenic activities affects soils quality. Industrialized countries have many contaminated sites; their remediation is a priority in environmental legislation. The aim of this overview is to consider the evolution of soil remediation from consolidated invasive technologies to environmentally friendly green strategies. The selection of technology is no longer exclusively based on eliminating the source of pollution but aims at remediation, which includes the recovery of soil quality. \u201cGreen remediation\u201d appears to be the key to addressing the issue of remediation of contaminated sites as it focuses on environmental quality, including the preservation of the environment. Further developments in green remediation reflect the aim of promoting clean-up strategies that also address the effects of climate change. Sustainable and resilient remediation faces the environmental challenge of achieving targets while reducing the environmental damage caused by clean-up interventions and must involve an awareness that social systems and environmental systems are closely connected

Selenium Enrichment Enhances the Quality and Shelf Life of Basil Leaves

The biofortification of leafy vegetables with selenium (Se) is a good way to increase human dietary Se intake. In addition, selenium delays plant senescence by enhancing the antioxidant capacity of plant tissues, decreasing postharvest losses. We investigated the eects of selenium addition on the production and quality of sweet basil (Ocimum basilicum) leaves of two harvesting phases, hereafter referred to as cuts, during the crop cycle. Plants were hydroponically grown and treated with 0 (control), 4, 8 and 12 mg Se L1 as selenate. To evaluate the growth, nutritional value and quality of the basil leaves, selected qualitative parameters were determined at harvest and after five days of storage. Application of Se at varying rates (4, 8 and 12 mg L1) was associated with an increased leaf selenium concentration in the first, but not the second cut. The application of Se significantly aected the antioxidant capacity as well as the total phenol and rosmarinic acid contents at harvest. The reduction in ethylene production observed in the plants at 4 mg Se L1 after five days of storage suggests that this Se treatment could be used to prolong and enhance the shelf-life of basil. The daily consumption of 10 g of Se-enriched basil leaves, which, as an example, are contained in a single portion of Italian pesto sauce, would also satisfy the recommended selenium supplementation in humans

Increase of the nutritional value of sweet basil (Ocimum basilicum L.) by selenium fertilization

Sweet basil (Ocimum basilicum L.) is an aromatic annual plant that has pharmaceutical properties and a culinary value. The essential oil components contained in basil leaves have antioxidant and antimicrobial activity. Selenium (Se) is an essential element for humans, and has an antioxidant and anticarcinogenic effect. Since healthful plant nutrients are more bioavailable than compounds contained in food supplements, the consumption of Se by humans can be increased by biofortification of fruiting and leafy vegetables. Further, Se appears to be effective in delaying fruit ripening and plant senescence, thus decreasing postharvest losses due to enhanced antioxidation. MATERIALS AND METHODS: We investigated the effect of Se addition on production and quality traits of Ocimum basilicum L. cv ‘Tigullio’. The experiments were conducted on sweet basil seedlings grown in greenhouse in hydroponics. Se was added to the nutrient solution as sodium selenate at different doses. In order to evaluated the growth, physiology and nutritional value of basil, the following parameters were determined at harvest time: plant biomass, antioxidant capacity, total phenols, rosmarinic acid, nitrate, macro- and micronutrients, total chlorophyll and total carotenoid. RESULTS: Leaf, stem and root selenium content increased by increasing the Se concentration in the nutrient solution. The rosmarinic acid content increased in basil plants treated with 1 and 4 mg Se L-1 Se if compared to control. Plant biomass and quality of product in general were unaffected by Se treatments. CONCLUSIONS: Se biofortification of basil allows to obtained basil leaves enriched in Se without decreasing the yield and the quality of the production. Our results suggest that the daily consumption of about 10 grams of basil enriched with 1-4 mg Se L-1 may provide a rational Se supplementation for human nutrition in accordance with the recommended dietary allowance (RDA) guidelines

Biofortification of Lettuce and Basil Seedlings to Produce Selenium Enriched Leafy Vegetables

Selenium (Se) biofortification of plants has been recognized as a good strategy to improve the nutritive value of vegetables and increase Se daily intake in humans. Identifying the most appropriate method to enrich plants is a key issue in the biofortification process. We tested a biofortification technique that produces Se enriched seedlings for transplant, yet barely modifies conventional cultivation techniques. Lettuce (Lactuca sativa L.) and sweet basil (Ocimum basilicum L.) were exposed to selenium by adding 0, 1 and 3 mg L−1 (lettuce) and 0, 2 and 3 mg L−1 (basil) of Se, as sodium selenate, to the growing substrate immediately after sowing. When seedlings reached an appropriate size, they were transplanted into the open field, and plants were grown until maturity. Lettuce and basil seedlings accumulated selenium without any reduction in leaf biomass at maturity. The highest dose of Se induced a higher antioxidant capacity and flavonoid content in both species at both sampling times. At maturity, biofortified plants still showed a higher leaf Se content compared to the control, and would be able to provide from 10% to 17% (lettuce) and from 9% to 12% (basil) of the adequate intake (AI) of Se