The Impact of the Inoculation of Different Pied de Cuve on the Chemical and Organoleptic Profiles of Wines.

Controlling the microorganisms involved in alcoholic fermentation during wine production can be achieved by adding a small quantity of spontaneously fermenting must to freshly crushed grapes, a technique known as pied de cuve (PdC). This method not only serves as an inoculation starter but also enhances the microbial footprint unique to each wine region. Recent studies have confirmed that wines inoculated with PdC exhibit efficient fermentation kinetics comparable to those inoculated with commercial strains of Saccharomyces cerevisiae. However, further research is required to draw robust conclusions about the chemical and sensory impacts of PdC-inoculated wines. In this study, we examined the chemical and sensory effects of the PdC technique across three different harvests: Muscat of Alexandria (Spain, harvests 2022 and 2023) and Sauvignon Blanc (Chile, harvest 2023). Each PdC was prepared using various stressors (sulfur dioxide, ethanol, and temperature). Our findings revealed that wines produced with PdC exhibited similar fermentation kinetics and sensory profiles to those inoculated with commercial strains. Notably, PdC fermentations resulted in lower concentrations of acetic acid compared to both the commercial strain and spontaneous fermentations. The sensory analysis indicated that PdC wines significantly differed from those made with commercial strains, with PdC wines displaying more pronounced tropical notes. These results suggest that the PdC technique, particularly when using specific stressors, can maintain desirable fermentation characteristics while enhancing certain sensory attributes, offering a viable alternative to traditional inoculation methods.

Influence of different stress factors during the elaboration of grape must's pieddecuve on the dynamics of yeast populations during alcoholic fermentation.

The pieddecuve (PdC) technique involves using a portion of grape must to undergo spontaneous fermentation, which is then used to inoculate a larger volume of must. This allows for promoting autochthonous yeasts present in the must, which can respect the typicality of the resulting wine. However, the real impact of this practice on the yeast population has not been properly evaluated. In this study, we examined the effects of sulphur dioxide (SO2), temperature, ethanol supplementation, and time on the dynamics and selection of yeasts during spontaneous fermentation to be used as PdC. The experimentation was conducted in a synthetic medium and sterile must using a multi-species yeast consortium and in un-inoculated natural grape must. Saccharomyces cerevisiae dominated both the PdC and fermentations inoculated with commercial wine yeast, displaying similar population growth regardless of the tested conditions. However, using 40 mg/L of SO2 and 1% (v/v) ethanol during spontaneous fermentation of Muscat of Alexandria must allowed the non-Saccharomyces to be dominant during the first stages, regardless of the temperature tested. These findings suggest that it is possible to apply the studied parameters to modulate the yeast population during spontaneous fermentation while confirming the effectiveness of the PdC methodology in controlling alcoholic fermentation.

Bacterial diversity analysis of freshwater sources for human use in rural areas of the tropical Andean region of Colombia / Análisis de la diversidad bacteriana en aguas superficiales usadas para consumo humano en zonas rurales de la región andina colombiana

Abstract Potable water supply and sanitization in rural areas in developing countries are still inadequate. The main risk associated with unsafe drinking water is the infection with pathogenic microorganisms. Objective: In this study, we investigate the bacterial diversity and the potentially pathogenic bacteria in water samples from diffe rent points of distribution in three rural villages from the Andean region of Colombia. Methods: Illumina libraries for water samples were prepared and sequenced using 300 bp paired-end MiSeq protocol, the bioinformatic analyses were performed with Mothur pipeline and the phyloseq package in Rstudio. Results: The mi crobial community composition showed statistically significant differences according to the village and the sample origin. Alpha, Beta, and Gammaproteobacteria were the dominant class detected in all water samples. The most relevant pathogenic genera detected in the surface were Legionella, Mycobacterium, Yersinia, Burkholderia, and Rickettsia. In the tap water samples, potential pathogens like Streptococcus, Staphylococcus, Corynebacterium, Nocardia, and Escherichia/Shige lla were detected.

Resumen El suministro y potabilización del agua de consumo humano en las zonas rurales de los países en vías de desarrollo sigue siendo limitado. El principal riesgo asociado con el uso de agua no potable es la infección con microorganismos patógenos. Objetivo: En este estudio se investigó la diversidad bacteriana y la presencia de bacterias potencialmente patógenas en muestras de agua de diferentes puntos de distribución en tres asentamientos rurales de la región andina de Colombia. Métodos: Se prepararon y secuenciaron bibliotecas de amplicones (rDNA 16S) para muestras de agua utilizando la plataforma Illumina MiSeq con lecturas pareadas de 300 bases. Los análisis bioinformáticos se realizaron con el programa Mothur y el paquete estadístico Phyloseq en Rstudio. Resultados: La composición de la comunidad microbiana mostró diferencias estadísticamente significativas según el sitio y el origen de la muestra. Alfa, Beta y Gammaproteobac terias fueron las clase dominantes detectadas en todas las muestras de agua. Los géneros patógenos más relevantes detectados fueron Legionella, Mycobacterium, Yersinia, Burkholderia y Rickettsia. En las muestras de agua del grifo se detectaron patógenos potenciales como Streptococcus, Staphylococcus, Corynebacterium, Nocardia y Escherichia /Shigella.

Metagenomic Analysis of Biocide-Treated Neotropical Oil Reservoir Water Unveils Microdiversity of Thermophile Tepidiphilus.

Microorganisms are capable of colonizing extreme environments like deep biosphere and oil reservoirs. The prokaryotes diversity in exploited oil reservoirs is composed of indigenous microbial communities and artificially introduced microbes. In the present work, high throughput sequencing techniques were applied to analyze the microbial community from the injected and produced water in a neotropical hyper-thermophile oil reservoir located in the Orinoquia region of Colombia, South America. Tepidiphilus is the dominant bacteria found in both injection and produced waters. The produced water has a higher microbial richness and exhibits a Tepidiphilus microdiversity. The reservoir injected water is recycled and treated with the biocides glutaraldehyde and tetrakis-hydroxymethyl-phosphonium sulfate (THPS) to reduce microbial load. This process reduces microbial richness and selects a single Tepidiphilus genome (T. sp. UDEAICP_D1) as the dominant isolate. Thermus and Hydrogenobacter were subdominants in both water systems. Phylogenomic analysis of the injection water dominant Tepidiphilus positioned it as an independent branch outside T. succinatimandens and T. thermophilus lineage. Comparative analysis of the Tepidiphilus genomes revealed several genes that might be related to the biocide-resistant phenotype and the tolerance to the stress conditions imposed inside the oil well, like RND efflux pumps and type II toxin-antitoxin systems. Comparing the abundance of Tepidiphilus protein-coding genes in both water systems shows that the biocide selected Tepidiphilus sp. UDEAICP_D1 genome has enriched genes annotated as ABC-2 type transporter, ABC transporter, Methionine biosynthesis protein MetW, Glycosyltransferases, and two-component system NarL.

Annual microbial community dynamics in a full-scale anaerobic sludge digester from a wastewater treatment plant in Colombia.

Anaerobic digestion is a microbe-driven process widely applied to treat activated sludge from municipal wastewater treatment plants. It is one of the most efficient solutions for sludge reduction along with biogas production. However, the knowledge of the microbial consortium involved in this process is still unknown in full-scale anaerobic digesters from Latin America. This study aimed to elucidate the dynamics of the microbial community of a full-scale anaerobic digester for a year using 16S rDNA amplicon sequencing with the Illumina Miseq platform. The results showed fluctuations in the frequencies of dominant phyla with a decrease of Proteobacteria and Bacteroidetes after a temporary suspension of anaerobic digester. The core community was affiliated with bacterial phyla Firmicutes, Actinobacteria, Proteobacteria, and Chloroflexi. The core community was represented by 154 OTUs that accounted for 74% of all the processed reads. The Anaerolineaceae family, within Chloroflexi phylum, was the most frequently observed taxonomic group in all samples analyzed. Despite the microbial fluctuations, the biogas production was stable over the studied year (average 66% methane production), which might indicate a functional redundancy in the microbial consortium.

Metagenomic assessment of the microbial community and methanogenic pathways in biosolids from a municipal wastewater treatment plant in Medellín, Colombia.

Abundance and diversity of microbial communities in biosolids are variable and poorly studied in the tropics, and it is known that rainfall is one of the events that could affect the phylogenetic and functional microbial structure. In the present study, using NGS technics, we studied the microbial diversity as well as the methanogenesis pathway in one of the largest WWTP in Colombia. Besides, we sampled and analyzed biosolids from rainy season and dry season. Phylogenetic classification showed a predominance of bacteria in both samples and difference in the dominant groups depending on the rainfall season. Whereas Pseudomonas was the dominant bacteria in the dry season, Coprothermobacter was in the rainy season. Archaea abundance was higher in the rainy season (11.5%) doubling dry season proportion. The bioreactor biogas production and total solids content showed similar results between rainy and dry season at the sampling dates. The most abundant Archaea related with methanogenesis was Methanosaeta, which is a methanogenic microorganism that exclusively uses acetate to produce methane. Moreover, annotation of the methanogenic pathway in the metagenome showed abundance in genes encoding Acetyl-CoA synthetases (ACSS), an enzyme that catalyzes acetate activation. Our results suggest that the microbial diversity was stable among the two time points tested, rainy season and dry season; and, although there were changes in the microbial abundance of dominant bacterial species, anaerobic digester performance is not affected.

[First isolate of Encephalitozoon intestinalis from stools of a Colombian patient with AIDS]. / Primer aislamiento de Encephalitozoon intestinalis a partir de muestra de materia fecal de un paciente colombiano con sida.

INTRODUCTION: Microsporidia are obligate intracellular parasites that are recognized as important opportunistic pathogens of immunocompromised and transplanted patients. Enterocytozoon bieneusi and, less frequently, Encephalitozoon intestinalis are the most prevalent species in humans; both of them are associated with enteric infections. Cell cultures have been useful in the study of microsporidia biology. In Colombia, however, no isolates of microsporidia from patients with AIDS have been obtained. OBJECTIVE: A cell culture of intestinal microsporidia was established from stools of positive patients in order to isolate a native strain. MATERIALS AND METHODS: Stool from a single AIDS patient was concentrated with the water-ether technique, and the sediment was treated with a mixture of antibiotics and antifungal agents for 18 hours at 37 degrees C. Vero cells were cultivated in 24-well plates with Gibco RPMI medium supplemented with 10% bovine fetal serum and antibiotics. The culture was subsequently inoculated with previously concentrated spores. The medium was changed every second day and the presence of spores was evaluated with the Quick Hot Gram chromotrope stain. RESULTS: Two weeks post-infection, microsporidial spores were identified with characteristic morphology and staining properties. PCR results showed that Encephalitozoon intestinalis was the isolated species. CONCLUSIONS: A cell culture of microsporidia was established from a stool sample. This protocol is important to isolate and maintain additional native Colombian strains and it will contribute to biochemical, immunological and epidemiological studies of the currently established strain.

Primer aislamiento de Encephalitozoon intestinalis a partir de muestra de materia fecal de un paciente colombiano con sida / First isolate of Encephalitozoon intestinalis from stools of a Colombian patient with AIDS

Introducción. Los microsporidios son agentes de infecciones oportunistas en pacientes con sida y con trasplantes, principalmente. Enterocytozoon bieneusi y Encephalitozoon intestinalis son los más frecuentes, asociados con infecciones entéricas. Los cultivos celulares han contribuido al conocimiento de los microsporidios. En Colombia no se han obtenido aislamientos provenientes de pacientes con microsporidiosis y, por consiguiente, no existen cepas autóctonas de los mismos. Objetivo. Establecer el cultivo celular de microsporidios intestinales a partir de materia fecal de pacientes parasitados. Materiales y métodos. Se realizó concentración agua-éter de la materia fecal positiva para microsporidios y el sedimento resultante se trató con una mezcla de antibióticos y antimicóticos durante 18 horas a 37 oC. Se inocularon células Vero previamente cultivadas en placas de 24 pozos y en medio RPMI con suplemento de suero bovino fetal al 10 por ciento y antibióticos, con las esporas concentradas. Los cultivos se mantuvieron a 37 oC al 5 por ciento de CO2. Se cambió de medio cada dos días y se evaluó la presencia de esporas en los sobrenadantes mediante Gram-cromótropo rápido en caliente. Resultados. En la segunda semana después de la infección, se encontraron esporas de microsporidios con morfología y coloración características. Mediante PCR se determinó que el microsporidio encontrado correspondía a la especie E. intestinalis. Conclusión. Se estableció el cultivo in vitro de microsporidios de materia fecal. Este protocolo es importante para la obtención y el mantenimiento de cepas autóctonas en Colombia, y contribuirá a las investigaciones de aspectos bioquímicos, inmunológicos y epidemiológicos de dichas cepas.