Since the Middle Ages, citrus essential oils (EOs) have been widely used for their bactericidal, virucidal, fungicidal, antiparasitical, insecticidal, medicinal and cosmetic proprieties. Also nowadays, they find important applications in pharmaceutical, sanitary, cosmetic, agricultural and food industries. The best method to extract EOs from citrus plant tissue is steam distillation because of a variety of extracted volatile molecules such as terpenes and terpenoids, phenol-derived aromatic components and aliphatic components. In vitro physicochemical assays classify most of them as antioxidants.

Wastewater treatment plants (WWTPs) require an urgent transition from a linear to a circular economy operation/design concept with a consequent resource recovery and more sustainable waste management. Natural resources have to be preserved, and wastes have to become an opportunity for recovering resources and materials (water reuse, energy, sludge reuse). However, the transition toward a circular economy is a complex and long process due to the existence of technical, economic, social and regulatory barriers. These existing barriers are critical challenges for a modern and sustainable WWTP concept. The recovery of resources must be considered a strategic target from the earliest process-design phase. In this context, the European Union’s Horizon 2020 project “Achieving wider uptake of water-smart solutions—WIDER UPTAKE” aims to overcome the existing barriers (technological, regulatory, organizational, social and economic) toward the transition from a linear to a circular economy model for WWTPs. This study is aimed at increasing the awareness of the existing barriers to a circular economy and summarizes the key contributions of the WIDER UPTAKE project in terms of water reuse, sludge reuse and nutrient recovery.

Cover crop (CC) management in vineyards increases sustainability by improving soil chemical and biological fertility, but knowledge on its effects in semiarid soils is lacking. This study evaluated the effect of leguminous CC management on soil organic carbon (SOC) sequestration, soil nitrate content and microbial diversity in a semiarid vineyard, in comparison to conventional tillage (CT). SOC and nitrate were monitored during vine-growing season; soil respiration, determined by incubation experiments, microbial biomass and diversity was analyzed after CC burial. The microbial diversity was evaluated by bacterial and fungal automated ribosomal intergenic spacer analysis (ARISA) and high-throughput sequencing of 16SrDNA. CC increased nitrate content and, although it had no relevant effect on SOC, almost doubled its active microbial component, which contributes to SOC stabilization. An unexpected stability of the microbial communities under different soil managements was assessed, fungal diversity being slightly enhanced under CT while bacterial diversity increased under CC. The complete nitrifying genus Nitrospira and plant growth-promoting genera were increased under CC, while desiccation-tolerant genera were abundant in CT. Findings showed that temporary CC applied in semiarid vineyards does not optimize the provided ecosystem services, hence a proper management protocol for dry environments should be set up.

Eggplant berries are a source of health-promoting metabolites including antioxidant and nutraceutical compounds, mainly anthocyanins and chlorogenic acid; however, they also contain some anti-nutritional compounds such as steroidal glycoalkaloids (SGA) and saponins, which are responsible for the bitter taste of the flesh and with potential toxic effects on humans. Up to now, Quantitative Trait Loci (QTL) for the metabolic content are far from being characterized in eggplant, thus hampering the application of breeding programs aimed at improving its fruit quality. Here we report on the identification of some QTL for the fruit metabolic content in an F2 intraspecific mapping population of 156 individuals, obtained by crossing the eggplant breeding lines ‘305E40’ x ‘67/3’. The same population was previously employed for the development of a RAD-tag based linkage map and the identification of QTL associated to morphological and physiological traits. The mapping population was biochemically characterized for both fruit basic qualitative data, like dry matter, °Brix, sugars and organic acids, as well as for health-related compounds such chlorogenic acid, (the main flesh monomeric phenol), the two peel anthocyanins (i.e. delphinidin-3-rutinoside (D3R) and delphinidin-3-(p-coumaroylrutinoside)-5-glucoside (nasunin)) and the two main steroidal glycoalkaloids, solasonine and solamargine. For most of the traits, one major QTL (PVE ≥ 10%) was spotted and putative orthologies with other Solanaceae crops are discussed. The present results supply valuable information to eggplant breeders on the inheritance of key fruit quality traits, thus providing potential tools to assist future breeding programs.