Biology subjects

Del Valle, E. E.

Publications and source records attributed to Del Valle, E. E..

3 recordsLinked to original sources

bioRxiv2026

Draft Genome Sequence of Bacillus pergaminensis sp. nov. strain Bva_UNVM-123: A Promising Candidate for Bioremediation.

The Bacillus genus comprises physiologically versatile, endospore-forming bacteria widely distributed in natural environments. In this study, we report the isolation and genomic characterization of strain Bva_UNVM-123, recovered from agricultural soil in Pergamino, Argentina. Whole-genome sequencing using Illumina technology yielded a 5.1 Mbp draft genome assembled in 67 contigs with a GC content of 36%. Comparative genomic analyses using the TYGS server and digital DNA-DNA hybridization (dDDH) values supported its classification as a potentially novel species within the Bacillus sensu lato (s.l.) group. Genome annotation revealed 4,866 protein-coding genes, including multiple determinants conferring resistance to antibiotics (e.g., fosfomycin, tetracycline, beta-lactams) and toxic heavy metals (e.g., arsenic, cadmium, mercury), supporting its potential application in bioremediation. Additionally, PathogenFinder predicted a low probability of human pathogenicity (0.207), reinforcing its safety for environmental use. Functional classification based on Swiss-Prot further supported a metabolically versatile profile and revealed the presence of resistance-related categories associated with environmental adaptation. This study adds to the growing knowledge of environmental Bacillus species and their biotechnological potential.

microbiology↗

bioRxiv2026

Exploratory 16S rRNA Metagenomic Analysis of Soil Microbial Communities in Agroecosystems of North-Central Argentina

Agriculture has modified the soil structure due to the influence of external factors and processes that affect microbial biodiversity. Metagenomics is a fundamental tool for the study of soil microbial diversity because it provides information about the ecosystem diversity, including both the microorganisms that cannot be isolated in culture media and those that are no longer viable in the analyzed sample. In this work, six soil samples obtained from agroecosystems of central and northern Argentina were subjected to a preliminary 16S metagenomic analysis. Copiotrophic bacteria (Proteobacteria and Actinobacteriota) were dominant and one of the samples had a dominance of an oligotrophic Phylum (Acidobacteria). Our findings support previous evidence from traditionally managed agroecosystems and provide new insights into the diversity of soil microbiomes in Argentine regions outside the Pampas. Finally, we analyzed the most common genera with relevant species to agronomy, both beneficial and pathogenic, and their abundance and diversity in the sequenced samples.

genetics↗

bioRxiv2024

Bacillus toyonensis biovar Thuringiensis: an overlooked entomopathogen?

Horizontal gene transfer (HGT) significantly influences prokaryotic genome evolution. Bacillus cereus and Bacillus thuringiensis are nearly identical at the chromosomal level, except for B. thuringiensis producing parasporal crystals. The genes for these crystal proteins (e.g., cry1A), along with other encoded insecticidal proteins (e.g., vip3A), are located on megaplasmids and can be horizontally transferred. Recently, Sauka et al. (2022) reported a Bacillus toyonensis strain that produces parasporal crystals with dual insecticidal activity. This strain was classified as Bacillus toyonensis biovar Thuringiensis (NCBI: txid2923195) following Carroll et al.s (2020) nomenclature. Misclassified B. toyonensis strains, previously identified as B. thuringiensis (e.g., strain MC28), encode cry and cyt genes toxic to lepidopteran and dipteran insects. Advances in genome sequencing and bioinformatics tools now reduce misidentifications, enabling accurate reclassification in databases like GenBank. These findings highlight the need for genome-based taxonomic reassessment within the Bacillus cereus group and clarify the chromosomal placement of crystal-forming B. toyonensis strains.

evolutionary biology↗