Currently, agricultural waste is proposed as a sustainable alternative in the removal of heavy metals present in industrial wastewater, to fulfill some of the goals proposed in the Sustainable Development Goals stated for the 2030 Agenda, in particular in Sections 3.9 and 6.9. Considering this context, the coffee pulp (Castilla variety) of Caldas municipality (Colombia) was used in study for the removal of one of the most toxic chemical species of chromium: Cr (VI). Therefore, the agricultural residue was subjected to a bromatological characterization, determination of the lignocellulosic composition and elucidation of characteristic organic functional groups by IR spectrophotometry. Additionally, the optimal parameters for contaminant removal were identified, regarding particle size, biomass quantity, optimum pH, stirring time, temperature, adsorption kinetics, zero charge potential (pH_pzc) and adsorption isotherms, to analyze the kinetic model that fitted the process, the explanation of the possible adsorption mechanism between the contaminant, the surface of the coffee pulp and the capacity of maximum adsorption, respectively. Finally, the innovation of the research is discussed considering two criteria: First, when a mixture was made in different proportions between two agricultural residues (coffee pulp and plantain pseudostem) to show if there was an increase in the removal of the contaminant under the same optimal conditions found experimentally; and the second criterion, the comparison of the maximum adsorption capacity, with the percentages of removal carried out by other authors using the pulp of unmodified coffee.

Spearmint (Mentha spicata L.) has been widely studied for its diversity of compounds for product generation. However, studies describing the chemical and biological characteristics of commercial spearmint materials from different origins are scarce. For this reason, this research aimed to bioprospecting spearmint from three origins: Colombia (Col), Mexico (Mex), and Egypt (Eg). We performed a biological activity analysis, such as FRAP, DPPH, and ABTS, inhibition potential of S. pyogenes, K. pneumoniae, E. coli, P. aeuroginosa, S. aureus, S aureus Methicillin-Resistant, and E. faecalis. Furthermore, we performed chemical assays, such as total polyphenol and rosmarinic acid, and untargeted metabolomics via HPLC-MS/MS. Finally, we developed a causality analysis to integrate biological activities with chemical analyses. We found significant differences between the samples for the total polyphenol and rosmarinic acid contents, FRAP, and inhibition analyses for Methicillin-Resistant S. aureus and E. faecalis. Also, clear metabolic differentiation was observed among the three commercial materials evaluated. These results allow us to propose data-driven uses for the three spearmint materials available in current markets.

Fue evaluada la presencia de bacterias fijadoras de nitrógeno (diazotróficas) en tres mezclas de residuos con proporciones diferentes de compost de cachaza, arena y carbonilla; proporciones iguales de cascarilla de arroz y bagazo de caña: M1 (40, 10, 10, 20, 20 respectivamente), M2 (20, 0, 40, 20, 20 respectivamente), M3 (10, 40, 10, 20, 20 respectivamente). La evaluación se basó en la presencia del gen nifH, característico exclusivamente en bacterias diazotróficas. Se utilizó como control positivo muestras de ADN de bacterias del genero Azotobacter spp. Las mezclas con mayor contenido de cachaza y carbonilla M1 y M2, amplificaron para el gen nifH. Las bandas más fuertes se observan en M1 con mayor contenido de compost de cachaza. En contraste la mezcla M3, conformada principalmente por arena y cantidad muy inferior de residuos orgánicos no amplificó; sugiriendo que los contenidos de materia orgánica, son relevantes para la presencia de bacterias diazotróficas y potencial estimulante de fijación biológica de nitrógeno.