Despite the blitz on chemical-based fertilizers, the transition towards the bio-based fertilizers may subvert fossilfuels-based fertilizers. Research efforts are perpetrated to contend the transition towards sustainable agriculture, thus, enhancing the bio-based economy. Bioprotective agents are key players for alternative farming as environmentally-friendly applications. This mini-review provides a consolidated briefing of lactic acid bacteria production with the main focus on their impact on human health.

Critical metals, which mainly include the platinum group of metals, and the rare earth elements, have gained much importance because these elements are essential for economic development. A matter of concern is their availability, which is scarce, and so a constant supply is at risk. Bioleaching is one of the commonly used methods to extract these critical metals from various sources, such as industrial wastewater and mining water. In this study, we have discussed the mechanisms of bioleaching, the factors that affect bioleaching, and a correlation between the extraction of the critical metals using microalgae which has many positive aspects. The review also suggests the future prospects for the use of microalgae in the extraction of critical metals.

Sustainability has become strategic since companies are aware that they must make a positive contribution to society and the environment in which they operate. At the same time, alliances have been formed and pacts have been made among nations to attempt to solve the social, economic and environmental problems that today’s society faces. This is the case of the UN’s 2030 Agenda and the Sustainable Development Goals (SDGs). This action plan entails the development of different initiatives to help face the challenges of this century, which have increased notably with the COVID-19 pandemic. The objective of this study is to carry out an analysis of Spanish companies’ commitment to the 2030 Agenda and the SDGs and verify what types of activities they propose to ratify their commitment in an uncertain period for firms. For a sample of 100 observations of Spanish firms in 2020 and 2021, we evidence that SDGs 4 (Quality education), 8 (Decent work and economic growth), 9 (Industry, innovation, and infrastructure), 13 (Climate action) and 17 (Partnerships for the goals) have been adopted by many companies, which have presented initiatives, projects and programmes to achieve their goals. Commitment to the SDGs had a positive evolution in 2021, i.e., firms created economic value, protected the environment and contributed to greater social well-being. Our results show companies’ preferences in terms of stakeholders as their SDGs’ actions focus on women, older people, young people, workers and trade unions, local governments and researchers in issues related to climate change. The paper contributes with a global assessment of companies’ initiatives and helps to determine the impact of uncertain environments on business commitments to the 2030 Agenda.

Remanufacturing industry gives an opportunity to rework defective products from a production system and make them useful again. When an industry remanufactures multiple similar types of products, every type of product goes through the same procedure repetitively. Repetition of the same procedure for similar products causes the overuse of a machine. This study investigates a flexible production system to reduce the overuse of machines for repetitive tasks. A two-stage flexible production system is considered where the common parts of multiple products are produced and remanufactured in the Stage 1. Continuing from Stage 1, the rest product-specific production of each product and remanufacturing processes are completed in Stage 2. Transportation of products uses a multiple delivery policy. This study aims to optimize the cycle time for the production process along with the production rate for Stages 1 and 2. The model is solved by a classical optimization technique and numerical results find the minimum cost of the remanufacturing system. A linear along with non-linear relationship effect of the shared-production process on the production cost are discussed. Results show that the two-stage production system with a shared-production process is cost-efficient and reduce the cycle time.

Rural areas are essential to moving towards the necessary sustainable energy transition and climate change mitigation through renewable energy (RE) technologies. However, RE planning and decision-making in rural locations have not been developed to date with a focus on the local level and accompanied by a careful and thorough assessment of the simultaneous availability of alternative RE sources in a specific territory. Quite differently, RE investments in rural locations have been primarily driven by the interests of large power utilities to exploit a particular RE source, with benefits escaping from the rural economies to end up in the income statements of those large corporations. There is a need to approach RE planning at the municipal scale considering the availability of alternative RE sources. This study suggests the development of a rural RE potential index that could help in the identification of appropriate locations for the implementation of hybrid renewable energy systems (HRESs). The construction of a composite indicator to measure rural RE potential is exemplified through a case study that deals with ten indicators in the context of Galician rural municipalities, involving different RE potentials and some technical or regulatory constraints. Equal weighting and Principal Component Analysis are considered alternative methods for the index construction. Municipalities are the relevant local decision level where energy policy should be focused in order to diversify both the RE mix and the investor base. The proposed index could be the basis for future analyses aimed at optimizing the design and implementation of HRESs in rural environments at a local-regional-national scale.

Trees growing in natural and managed environments have the capacity to act as conduits for the transport of greenhouse gases produced belowground to the atmosphere. Nitrous oxide (N₂O) emissions have been observed from tree stems in natural ecosystems but have not yet been measured in the context of forested former landfill sites. This research gap was addressed by an investigation quantifying stem and soil N₂O emissions from a closed UK landfill and a comparable natural site. Measurements were made by using flux chambers and gas chromatography over a four-month period. Analyses showed that the average N₂O stem fluxes from the landfill and non-landfill sites were 0.63 ± 0.06 µg m^–2 h^–1 and 0.26 ± 0.05 µg m^–2 h^–1, respectively. The former landfill site showed seasonal patterns in N₂O stem emissions and decreasing N₂O fluxes with increased stem sampling position above the forest floor. Tree stem emissions accounted for 1% of the total landfill N₂O surface flux, which is lower than the contribution of stem fluxes to the total surface flux in dry and flooded boreal forests.