Biology subjects

Saenz, J. S.

Publications and source records attributed to Saenz, J. S..

4 recordsLinked to original sources

bioRxiv2025

Critical Assessment of MetaProteome Investigation 2 (CAMPI-2): Multi-laboratory assessment of sample processing methods to stabilize fecal microbiome for functional analysis

BackgroundFecal samples are widely used as a proxy for studying gut microbiome composition in both human and animal research. Fecal metaproteomics provides valuable insights by tracking changes in the relative abundance of microbial taxa and their protein functions. To ensure reliable results, it is crucial to minimize alterations in the metaproteome occurring from sample collection to protein extraction. Therefore, employing effective stabilization methods is essential to preserve the integrity of the fecal metaproteome from sample collection to laboratory analysis, particularly over long distances or when rapid freezing options are not readily available. In line with these needs, the second edition of the Critical Assessment of MetaProteome Investigation (CAMPI-2) was specifically focused on testing sample stabilization protocols to be applied before metaproteomic analysis. ResultsThis collaborative multicenter study assessed the ability of five different stabilization methods, based on two commercial devices and three specific reagents (acetone, lithium dodecyl sulfate, and an RNAlater-like buffer), respectively, to stabilize the fecal metaproteome during room-temperature storage (14 days) and shipment to mass spectrometry facilities. The five methods were tested simultaneously by eight different laboratories across Europe, using aliquots from the same fecal sample. After protein extraction and digestion, duplicate aliquots of the resulting peptides were analyzed independently by two mass spectrometry facilities at distinct international locations. Analysis of the mass spectrometric data using two different search engines revealed that the fecal metaproteome profile differed considerably depending on the stabilization method used in terms of richness, alpha and beta diversity, reproducibility, and quantitative distribution of main taxa and functions. Although each method showed unique strengths and weaknesses, a commercial swab-based device stood out for its remarkable reproducibility and ranked highest for most of the metrics measured. ConclusionsCAMPI-2 allowed a robust evaluation of five different methods for preserving fecal metaproteome samples. The present investigation provides useful data for the design of metaproteomics and multi-omics studies where fecal sampling cannot be immediately followed by long-term storage at -80{degrees}C. Further optimization of the tested protocols is necessary to improve stabilization efficiency and control bias in the taxonomic and functional profile of the gut microbiome.

microbiology↗

bioRxiv2024

Antiviral defence systems in the rumen microbiome

The continuous interaction between phages and their respective hosts has resulted in the evolution of multiple bacterial immune mechanism. However, the diversity and prevalence of antiviral defence systems in complex communities is still unknown. We therefore investigated the diversity and abundance of viral defence systems in 3038 high-quality bacterial and archaeal genomes from the rumen. In total, 14,241 defence systems and 31,948 antiviral-related genes were identified. Those genes represented 114 unique system types grouped into 49 families. We observed a high prevalence of defence systems in the genomes. However, the number of defence systems, defence system families and systems density varied widely from genome to genome. Additionally, the number of defence system correlated positively with the number of defence systems families and the genome size. Restriction modification, Abi and cas system families were the most common, but many rare systems were present in only 1% of the genomes. Antiviral defence systems are prevalent and diverse in the rumen, but only a few are dominant, indicating that most systems are rarely present. However, the collection of systems throughout the rumen may represent a pool of mechanisms that can be shared by different members of the community and modulate the phage-host interaction. ImportancePhages may act antagonistically at the cell level but have a mutualistic interaction at the microbiome level. This interaction shapes the structure of microbial communities and is mainly driven by defence mechanism. However, the diversity of such mechanism is larger than previously thought. Because of that, we described the abundance and diversity of antiviral defence system of a collection of genomes, from the rumen. While defence mechanisms seem to be prevalent among bacteria and archaea, only a few were common. This suggests that most of these defence mechanisms are not present in many rumen microbes but could be shared among different members of the microbial community. This aligned with the pan-immune system model, which appears to be common across different environments.

microbiology↗

bioRxiv2023

Novel taxonomic and functional diversity of bacteria from the upper digestive tract of chicken

Strategies to increase the production rate of chicken for human consumption alter the natural process of microbial colonisation and the nutritional performance of the animal. The lack of sufficient reference genomes limits the interpretation of sequencing data and restrain the study of complex functions. In this study, 43 strains obtained from crop, jejunum and ileum of chicken were isolated, characterised and genome analysed to observe their metabolic profiles, adaptive strategies and to serve as future references. Eight isolates represent new species that colonise the upper gut intestinal tract and present consistent adaptations that enable us to predict their ecological role, expanding our knowledge on the adaptive functions. Molecular characterisation confirmed the classification of Clostridium anaerovisceris sp. nov. (DSM 113860= LMG 32675), Clostridium butanolproducens (DSM 115076= LMG 32878), Ligilactobacillus hohenheimius sp. nov. (DSM 113870= LMG 32876), Limosilactobacillus gallus sp. nov. (DSM 113833 =LMG 32623), Limosilactobacillus avium sp. nov. (DSM 113849= LMG 32671), Limosilactobacillus pullum sp. nov. (DSM 115077 =LMG 32877), Limosilactobacillus digestus sp. nov. (DSM113835= LMG 32625) and Limosilactobacillus difficile sp. nov. (DSM 114195= LMG 32875). Strains of Limosilactobacillus were found to be more abundant in the crop, while Ligilactobacillus dominated the ileal digesta. Isolates from crop encode a high number of glycosidases specialized in complex polysaccharides compared to strains isolated from jejunum and ileum. These results represent the first approach for the isolation and detection of bacteria from the chickens upper digestive tract and describe the functional diversity of bacteria inhabiting these regions, improving the potential handling of chicken microbiota with biotechnological applications.

microbiology↗

bioRxiv2020

Leave no stone unturned: The hidden potential of carbon and nitrogen cycling by novel, highly adapted Thaumarchaeota in the Atacama Desert hyperarid core

The hyperarid core of the Atacama Desert is an extremely harsh environment previously thought to be colonized by only a few heterotrophic bacterial species. In addition, carbon and nitrogen cycling in these highly oligotrophic ecosystems are poorly understood. Here we genomically resolved a novel genus of Thaumarchaeota, Ca. Nitrosodesertus, found below boulders of the Atacama hyperarid core, and used comparative genomics to analyze their pangenome and site-specific adaptations. Their genomes contain genes for ammonia oxidation and the 3-hydroxypropionate/4-hydroxybutyrate carbon fixation pathway, indicating a chemolithoautotrophic lifestyle. Ca. Nitrosodesertus possesses the capacity for tolerating extensive environmental stress highlighted by the presence of genes against oxidative stress, DNA damage and genes for the formation of biofilms. These features are likely responsible for their dominance in samples with extremely low water content across three different boulder fields and eight different boulders. Genome-specific adaptations of the genomes included the presence of additional genes for UV resistance, heavy metal transporters, multiple types of ATP synthases, and divergent genes for aquaporins. Our results suggest that Thaumarchaeota mediate important carbon and nitrogen cycling in the hyperarid core of the Atacama and are part of its continuous and indigenous microbiome.

genomics↗