The generation of energy through the transformation of polluting waste is a widely explored field and offers advances in green technologies. One of the promising technologies is Microbial Fuel Cells (MFCs). These cells can contain electroactive microorganisms that transform organic waste into electricity by transferring electrons from their metabolism. In this study, a new bacterium capable of producing electricity from the waste of the poultry sector and using copper electrodes, called Av_G1, was identified and isolated. It is phylogenetically related to Citrobacter freundii and Citrobacter Murlinae. This new strain was identified molecularly, biochemically, and phylogenetically; its physiological and morphological characteristics were also studied through a Scanning Electron Microscope (SEM). Biochemical determination was performed using Simmons Citrate Agar, Lysine Iron Medium (L.I.A.), Motility/Ornithine Test, Methyl Red indicator, Enzymes: oxidase and catalase, and Gram stain test. The phylogenetic inference was deduced by bioinformatics tools (MEGA X, JalView, Clustal Omega) and the genetic databases The Ribosomal Database Project—RDP and the National Center for Biotechnology Information (NCBI). A maximum current potential of 0.645 V, a maximum current density of 168.72 ± 14.07 mA/m², and a power density of 31.05 mW/m² were recorded. During the monitoring, the physicochemical parameters were taken: pH, Oxide Reduction Potential (ORP), Dissolved Oxygen (DO), conductivity, Total Solids (TDS), and average temperature were recorded. Therefore, the present study shows a new Gram-negative electrogenic bacterium, which can be used for electrochemical processes and applied in MFC with copper electrodes.

Microbial fuel cells (MFC) are electrochemical systems through which sustainable energy can be produced due to the degradation of organic matter using substrates with a varied chemical composition. The bioprocess that takes place inside the MFC takes advantage of the oxidation of organic matter. This process releases protons and electrons extracellularly, and the latter are transferred from the anode to the cathode generating bioelectricity. The MFC operating system produces energy due to the bacterial metabolism, through an electron transfer phenomenon that reflects into a bio energy conversion with minimal impacts on the environment. With the MFC system, it is possible to investigate the use of new residual substrates for energy production, the types of native microbial communities that develop during the degradation of specific compounds and the design of more efficient cells. In this research, copper and graphite were evaluated as low-cost electrodes using batch microbial fuel cells for 208 hours of operation, a data logger was used, and physicochemical parameters were taken during this period. The maximum power density presented was 14 mW/m2 with the graphite electrode and 6.7 mW/m2 with the copper electrode. Electrogenic bacteria were identified through biochemical and molecular tests such as bacterial culture, strain purification, DNA extraction and sequencing of microorganisms. The bacteria were uploaded to the NCBI gene data bank and the identity of these strains was identified: avian graphite 1 “Av_A1” (Pseudomonas aureginosa), avian graphite 2 “Av_A2” (Bacillus cereus) and avian copper 1 “AV_C1” (Bacillus tropicus). A dual chamber MFC was assembled, so each microbial cell can contain the residual substrate and the corresponding electron acceptor, both for the anodic and cathodic cell. These cells were separated by a Nafion® or Ultrex® membrane cation exchange membrane. The results showed us that optimal conditions for the generation of bioelectricity can be established in MFC cells, adding information to the literature on the behavior of bacteria that thrive in stressful environments such as copper and simple materials such as the graphite.

The presence, distribution, and degradation of microplastics (MPs) were evaluated in four high-altitude reservoirs of the Colca-Chilli water transfer system in Arequipa, Peru: El Pañe, Dique Los Españoles, Aguada Blanca, and El Frayle. In our study, the sampling points were classified into two groups according to their location within the Colca and Chilli River systems, which are separated by approximately 150 km. Climatological data from 2000 to 2023-including precipitation, wind speed, and solar irradiation-were analyzed to evaluate their influence on the presence, deposition, and degradation of microplastics (MPs). Wind patterns, particularly in arid zones such as Aguada Blanca and El Frayle, facilitated the airborne transport of MPs, whereas precipitation and temperature variability played a significant role in MPs distribution in wetter areas like El Pañe and Dique Los Españoles. MPs were detected in all reservoirs, with concentrations ranging from 2260 to 6440 MPs/m³. The majority of MPs were smaller than 1 mm, indicating advanced fragmentation, likely caused by prolonged exposure to wind, water, or solar irradiation, as well as extended transport processes from larger plastic debris. Fibers were the most abundant form of MPs (≥70 %), followed by amorphous particles and films. These particles were analyzed using μRaman and μFTIR to determine their chemical composition and morphological characteristics. The predominant polymers identified were cellulose, polyethylene terephthalate (PET), cellophane, and semisynthetic fibers such as rayon. Spectral analysis of PET revealed significant degradation, evidenced by a reduction in CO and CH functional groups. The decrease in ester groups compared to the blank, together with the emergence of -COOH functional groups, suggests degradation processes driven by environmental factors. The loss of hydrocarbon functional groups increased particle hydrophilicity, thereby facilitating sedimentation and enhancing interactions with microorganisms. SEM/EDS analyses further confirmed degradation, showing variations in carbon and oxygen content consistent with oxidative and hydrolytic processes. Among the reservoirs, El Frayle exhibited the highest polymer volume (694.3034 mm³/m³), suggesting either lower degradation rates or higher levels of pollution. Conversely, "El Pañe-in" recorded the highest MP count but a lower total volume, reflecting the predominance of smaller particles. These findings emphasize the importance of evaluating both particle abundance and volume when assessing MPs pollution and its environmental implications. Overall, this study provides new insights into MPs dynamics in high-altitude reservoirs and highlights the need for further research to develop effective mitigation strategies for these critical water resources.