Evaluation of comparative scenarios from different sites of chestnut production using life cycle assessment (LCA): Case study in the Beira Interior region of Portugal.

The evaluation of the environmental impacts of chestnut production in the Beira Interior region (Portugal) is accessed. The comparative life cycle assessment (LCA) was performed with the use of openLCA software with 16 Environmental Footprint (EF) impact categories retrieved from the AGRIBALYSE database. The system boundary was from "cradle-to-farm gate" and the functional unit was 1 ton of chestnut delivered to consumers (only wholesale buyers). The processes model for the production of agricultural machinery, pesticides, fertilizers, and materials was modeled based on surveys and existing literature. The data was gathered from four different production areas: Serra da Estrela, Malcata, Gardunha, and Plateau area. Each site has two selected representative producers inner 250 km2 square radius environment. The results showed that the average GHG emissions in the low-input group (Estrela and Gardunha) were 1.83 kg CO2-eq/ton with the energy burden (80-89%) as main contribution emissions and in the intensive-input group (Malcata and Plateau) were 2.61 kg CO2-eq/ton with the main contribution source of emissions are fertilizer (76-83%). Sensitivity analysis results indicate shift input material and cultivation activities in chestnut production systems can be possible for all study areas without reducing yield production. The suggestions in this article can be used by farmers, policymakers, and other stakeholders to adopt new alternative production scenarios.

Draft genome sequence of Pseudomonas psychrotolerans L19, isolated from copper alloy coins.

We report the draft genome sequence of Pseudomonas psychrotolerans strain L19, isolated from a European 50-cent copper alloy coin. Multiple genes potentially involved in copper resistance were identified; however, it is unknown if these copper ion resistance determinants contribute to prolonged survival of this strain on dry metallic copper.

Isolation and characterization of bacteria resistant to metallic copper surfaces.

Metallic copper alloys have recently attracted attention as a new antimicrobial weapon for areas where surface hygiene is paramount. Currently it is not understood on a molecular level how metallic copper kills microbes, but previous studies have demonstrated that a wide variety of bacteria, including Escherichia coli, Staphylococcus aureus, and Clostridium difficile, are inactivated within minutes or a few hours of exposure. In this study, we show that bacteria isolated from copper alloy coins comprise strains that are especially resistant against the toxic properties exerted by dry metallic copper surfaces. The most resistant of 294 isolates were Gram-positive staphylococci and micrococci, Kocuria palustris, and Brachybacterium conglomeratum but also included the proteobacterial species Sphingomonas panni and Pseudomonas oleovorans. Cells of some of these bacterial strains survived on copper surfaces for 48 h or more. Remarkably, when these dry-surface-resistant strains were exposed to moist copper surfaces, resistance levels were close to those of control strains and MICs for copper ions were at or below control strain levels. This suggests that mechanisms conferring resistance against dry metallic copper surfaces in these newly isolated bacterial strains are different from well-characterized copper ion detoxification systems. Furthermore, staphylococci on coins did not exhibit increased levels of resistance to antibiotics, arguing against coselection with copper surface resistance traits.

Antimicrobial metallic copper surfaces kill Staphylococcus haemolyticus via membrane damage.

Recently, copper (Cu) in its metallic form has regained interest for its antimicrobial properties. Use of metallic Cu surfaces in worldwide hospital trials resulted in remarkable reductions in surface contaminations. Yet, our understanding of why microbes are killed upon contact to the metal is still limited and different modes of action have been proposed. This knowledge, however, is crucial for sustained use of such surfaces in hospitals and other hygiene-sensitive areas. Here, we report on the molecular mechanisms by which the Gram-positive Staphylococcus haemolyticus is inactivated by metallic Cu. Staphylococcus haemolyticus was killed within minutes on Cu but not on stainless steel demonstrating the antimicrobial efficacy of metallic Cu. Inductively coupled plasma mass spectroscopy (ICP-MS) analysis and in vivo staining with Coppersensor-1 indicated that cells accumulated large amounts of Cu ions from metallic Cu surfaces contributing to lethal damage. Mutation rates of Cu- or steel-exposed cells were similarly low. Instead, live/dead staining indicated cell membrane damage in Cu- but not steel-exposed cells. These findings support a model of the cellular targets of metallic Cu toxicity in bacteria, which suggests that metallic Cu is not genotoxic and does not kill via DNA damage. In contrast, membranes constitute the likely Achilles' heel of Cu surface-exposed cells.