José Antonio García-Pérez

Las lombrices de tierra composteras desempeñan un papel clave en la descomposición de la materia orgánica, las especies epigeas del género Eisenia son utilizadas ampliamente para efectuar el proceso de lombricompostaje y como bioindicadores en los estudios toxicológicos. Sin embargo, la identidad taxonómica precisa de las especies (semejanza morfológica) representa un desafío y puede afectar la eficacia y función del proceso de lombricompostaje. En este estudio se determinó la identidad de lombrices presentes en 5 instalaciones de vermicompostaje de Veracruz y Quintana Roo, México, empleando análisis molecular basado en la secuenciación del gen mitocondrial COI. El análisis reveló la presencia de 2 especies, Eisenia andrei y Perionyx excavatus, descartando la presencia de Eisenia fetida, la especie asumida previamente por encargados de las plantas de lombricompostaje. Las distancias génicas fueron < 1.3%, mientras que las divergencias con E. fetida superaron 16%, lo que valida la delimitación específica. Nuestros resultados destacan la necesidad de integrar métodos moleculares en la identificación de lombrices de tierra para su uso en los estudios toxicológicos y fortalecer el manejo sostenible de residuos orgánicos.

High prices for differentiated coffees with unique flavor profiles have spurred research into processing methods to standardize coffee production and improve quality. Fermentation is a biotechnological tool that may enhance the sensory profile of coffee and boost its overall quality. Carbonic maceration, which uses constant pressure CO2, can be used as a technique to differentiate coffees. In this study, the physical and sensorial qualities of Coffea arabica (yellow caturra variety) beans, following carbonic maceration, were assessed. The experiment was carried out during the harvest 2021/22 at La Joya farm. Data were analyzed for both the physical quality of the green coffee beans and the cup quality (sensorial) based on the fermentation process and duration using ANOVA, Friedman and U Mann-Whitney tests, with a significance level of alpha = 0.05. All analyses were conducted using SPSS software version 25. The final score was influenced by both carbonic maceration and the duration of fermentation, with scores for zero-day compositions being lower than those for 5, 10 and 15 days. A significant difference in primary defects, based on the duration of fermentation, was observed. In conclusion, carbonic maceration improved both coffee qualities at day 5 compared to day zero (natural process). However, the physical quality is negatively affected after 10 and 15 days, while the sensory quality increases respectively.Key words: Fermentation; Temperatura; Pressure; Carbon dioxide; Time; Quality.

Background. The results of a review on the factors that affect nitrogen fixation in the Inga-café system are presented. The nitrogen contribution that the Inga Miller tree genus provides to shade coffee plantations and the factors that affect its stability in biological nitrogen fixation are scarcely recognized. This work delves into the ecological factors and glyphosate herbicides that can affect the symbiosis of Inga spp. with diazotrophic bacteria in their roots (rhizobia), which form nodules and carry out biological nitrogen fixation. Methodology. Different information sources such as EBSCO, Scopus and Google Schoolar were reviewed, with logical or Boolean data search. 183 papers were used to address the factors that affect the symbiosis between trees of the Inga genus and rhizobia. The findings were organized in: Inga Miller taxonomy, shade coffee plantations with Inga spp., symbiosis between Inga spp. and Bradyrhizobium spp., ecological factors that affect the functioning of the Inga spp.-rhizobia symbiosis and the agrochemical factor: glyphosate herbicide. Results. The genus Inga is recognized as a clade Mimosoideae nested in the subfamily Caesalpinioideae. Shade coffee plantations with Inga are established below 23º N and 30º S, up to 3,100 m.a.s.l. and the symbiont genus is predominantly Bradyrhizobium spp. whose ecological limits of Inga spp-rhizobia were: altitude [988.7-1,381.5 m.a.s.l.], annual precipitation [2,048.4-2,064.36 mm], temperature [20.39-21.93 ºC] and soil pH [4.88-5.42 pH]. Glyphosated herbicides, as an external stimulus, can reduce the benefit of biological nitrogen fixation and erode the soil by keeping it devoid of vegetation. Additionally, some Bradyrhizobium spp. (thiO gene), which oxidizes glyphosate to aminomethylphosphonic acid (AMPA), could be a potential glyphosate degrader in the soil. Implications. Shade coffee plantations with 205-250 trees per hectare of Inga spp. allow fixing around 45 kg of N ha-1 year-1. This review may allow the adoption of new observational or experimental studies of the Inga spp.-rhizobia symbiosis, to approach the performance that favors the biological fixation of nitrogen in shade coffee plantations. Conclusions. The review indicates that there is a specific association between Inga spp. and Bradyrhizobium spp., that ecological factors, including the agronomic management with glyphosated herbicides can decrease nitrogen fixation performance during the symbiosis between Inga spp. and rhizobia. No systematic studies of the symbiosis-environment-agrochemical interaction in shade coffee plantations were found.

We identified diverse bradyrhizobia having distinct ERIC-PCR genomic fingerprints from native American trees Inga vera and Lysiloma spp. In addition, two nodule isolates recovered from Lysiloma divaricatum seedlings inoculated with soil from the tropical house of a UK botanical garden were also identified as Bradyrhizobium. Genomes were obtained (with sizes around 9 Mb each) from nine Inga and Lysiloma bradyrhizobial isolates; plasmids were detected in two of the Inga strains analyzed. Average Nucleotide Identity of whole genomes revealed five novel Bradyrhizobium genomospecies from Mexican trees, while the UK isolates were identified as Bradyrhizobium cajani and Bradyrhizobium brasilense. Inga vera and Lysiloma isolates, despite their genetic distances and different hosts, shared a common set of nod genes that suggested that I. vera and Lysiloma bradyrhizobia produce fucosylated, methylated and carbamylated lipochitooligosaccharides. Uptake hydrogenase hup, hyp and secretion system genes were found in some of the isolates. Lysiloma strains were found to be ineffective on I. vera. Some of the isolates may be used as plant inoculants.

Information about the paper titled "RELATIONSHIP BETWEEN PARTICIPATION IN FEDERATED SPORTS AND RISK OF SCHOOL FAILURE AND DROP-OUT" at IATED Digital Library

A good bioindicator of soil health is one that perceives minor changes due to changes in soil management and leads to changes in the processes of the soil ecosystem. The aim was to evaluate the use of soil bioindicators in the determination of the utility of two different Cedrela odorata forestry management systems. The litter and soil samples were collected from the rhizosphere of a monoculture (with no fertilization nor irrigation), and a co-culture (with fertilization and irrigation) stand with Citrus latifolia. The soil and litter bioindicators measured were the activity of acetylesterase (FDA), acid phosphatase (AcPh), alkaline phosphatase (AlkPh), laccase, and the estimation of the potential net rate of carbon mineralization (PNRCM). The results indicated that soil enzyme activities (FDA and phosphatases) in the litter were sensitive to the different management system treatments. Enzymatic activity, per unit dry weight, was higher in litter of co-culture (FDA = 1.05 nkat g-1 AcPh = 1.33 nkat g-1; AlkPh = 03.0 nkat g-1) than in litter of monoculture (FDA = 0.617nkat g-1; AcPh = 0.40 nkat g-1; AlkPh = 0. 983 nkat g-1). Differences in soil total nitrogen content, organic matter (OM) content, and micronutrients were found. In general, the co-culture stand (with fertilization and irrigation) with C. latifolia showed the best results.