In this study, seed-surface-associated bacteria from fresh fruits of Capsicum spp. were analyzed to explore potential isolates for biocontrol of phytopathogenic fungal strains. A total of 76 bacterial isolates were obtained from three different species of chili pepper (C. annuum L., C. pubescens R. & P., and C. chinense Jacq.), and two isolates were selected via mycelial growth inhibition assays based on their production of volatile organic compounds (VOCs) against six fungal strains. Genomic analysis identified these isolates as Bacillus altitudinis CH05, with a chromosome size of 3,687,823 bp and with 41.25% G+C, and Bacillus tropicus CH13, with a chromosome size of 5,283,706 bp and with 35.24% G+C. Both bacterial strains showed high mycelial growth inhibition capacities against Sclerotium rolfsii, Sclerotinia sp., Rhizoctonia solani, and Alternaria alternata but lower inhibition capacities against Colletotrichum gloesporoides and Fusarium oxysporum. VOC identification was carried out after 24 h of fermentation with 64 VOCs for B. altitudinis CH05 and 53 VOCs for B. tropicus CH13. 2,5-Dimethyl pyrazine and acetoin had the highest relative abundance values in both bacterial strains. Our findings revealed that seed-surface-associated bacteria on Capsicum spp. have the metabolic ability to produce VOCs for biocontrol of fungal strains and have the potential to be used in sustainable agriculture.

The competitive colonization of bacteria on similar ecological niches has a significant impact during their establishment. The synthesis speeds of different chemical classes of molecules during early competitive colonization can reduce the number of competitors through metabolic effects. In this work, we demonstrate for the first time that Kosakonia cowanii Cp1 previously isolated from the seeds of Capsicum pubescens R. P. produced volatile organic compounds (VOCs) during competitive colonization against Pectobacterium aroidearum SM2, affecting soft rot symptoms in serrano chili (Capsicum annuum L.). The pathogen P. aroidearum SM2 was isolated from the fruits of C. annuum var. Serrano with soft rot symptoms. The genome of the SM2 strain carries a 5,037,920 bp chromosome with 51.46% G + C content and 4925 predicted protein-coding genes. It presents 12 genes encoding plant-cell-wall-degrading enzymes (PCDEWs), 139 genes involved in five types of secretion systems, and 16 genes related to invasion motility. Pathogenic essays showed soft rot symptoms in the fruits of C. annuum L., Solanum lycopersicum, and Physalis philadelphica and the tubers of Solanum tuberosum. During the growth phases of K. cowanii Cp1, a mix of VOCs was identified by means of HS-SPME-GC-MS. Of these compounds, 2,5-dimethyl-pyrazine showed bactericidal effects and synergy with acetoin during the competitive colonization of K. cowanii Cp1 to completely reduce soft rot symptoms. This work provides novel evidence grounding a better understanding of bacterial interactions during competitive colonization on plant tissue, where VOC synthesis is essential and has a high potential capacity to control pathogenic microorganisms in agricultural systems.

Chili powder is an important condiment around the world. However, according to various reports, the presence of pathogenic microorganisms could present a public health risk factor during its consumption. Therefore, microbiological quality assessment is required to understand key microbial functional traits, such as antibiotic resistance genes (ARGs). In this study, metagenomic next-generation sequencing (mNGS) and bioinformatics analysis were used to characterize the comprehensive profiles of the bacterial community and antibiotic resistance genes (ARGs) in 15 chili powder samples from different regions of Mexico. The initial bacterial load showed aerobic mesophilic bacteria (AMB) ranging between 6 × 10³ and 7 × 10⁸ CFU/g, sporulated mesophilic bacteria (SMB) from 4.3 × 10³ to 2 × 10⁹ CFU/g, and enterobacteria (En) from <100 to 2.3 × 10⁶ CFU/g. The most representative families in the samples were Bacillaceae and Enterobacteriaceae, in which 18 potential pathogen-associated species were detected. In total, the resistome profile in the chili powder contained 68 unique genes, which conferred antibiotic resistance distributed in 13 different classes. Among the main classes of antibiotic resistance genes with a high abundance in almost all the samples were those related to multidrug, tetracycline, beta-lactam, aminoglycoside, and phenicol resistance. Our findings reveal the utility of mNGS in elucidating microbiological quality in chili powder to reduce the public health risks and the spread of potential pathogens with antibiotic resistance mechanisms.

We are providing the genome sequence of Priestia aryabhattai SPCL1, a bacterial strain isolated from a heavy metal leachate-contaminated soil in Querétaro, México. The Illumina NovaSeq platform was used to sequence the whole genome and the sequencing data obtained, including assembly and annotation, were analyzed on the BV-BRC platform. The genome, comprising 41 contigs and approximately 5.6 million base pairs with a GC content of 37.58 mol % and 6131 protein-coding sequences. In addition, 6 contigs of 146,177 bp (36.77 mol % G + C), 126,627 bp (33.27 mol % G + C), 16,881 bp (34.13 mol % G + C), 9835 bp (34.67 mol % G + C), 7402 bp (36.54 mol % G + C) and 4590 bp (35.38 mol % G + C) were assembled as plasmids. This analysis of genomic data represents a valuable resource for increasing knowledge of this bacterial specie and for possible applications in its biological functions. The genome data was deposited at National Center for Biotechnology Information (NCBI) under accession number Bioproject ID PRJNA1377581, Bio Sample ID SAMN53794006 and genome accession number ID JBSVDB000000000.

Bacillus cereus is a Gram-positive bacterium with the ability to form spores and is found in different environments such as food and soil. We report the complete genome sequence of B. cereus Spbamp1 strain, isolated from soil contaminated with leachates in Querétaro, Mexico. The complete genome was sequenced using the Illumina Novaseq platform and 51 contigs were assembled using the BV-BRC platform, with a total of 5547,101 base pairs, GC content of 34.91%, and 5712 predicted protein-coding sequences. The Spbamp1 strain was shown to be closely related to B. cereus ATCC 14,579 with ANI values of 96.08% and dDDH values of 79.06%, confirming its taxonomic analysis. This whole-genome dataset represents a valuable tool for investigating the genetic determinants of virulence and antimicrobial resistance in this environmental strain of B. cereus. In addition, it helps to understand the possible mechanisms of co-selection between heavy metal tolerance and antibiotic resistance in contaminated environments.