Findings highlight the potential biotechnological relevance of culturable bacterial isolates recovered from historically mining-impacted soils and provide genomic resources for future studies on environmental remediation, sustainable agriculture, and industrial biotechnology.
Endophytic bacteria play an important role in plant growth promotion and stress tolerance, offering sustainable alternatives to chemical inputs in agriculture. In this study, an endophytic bacterial strain P1 was isolated and identified as Pseudomonas stutzeri , a plant-associated bacterium exhibiting multiple plant growth–promoting traits (PGPTs). Biochemical (qualitative and quantitative) and in vitro analyses demonstrated nitrogen fixation, phosphate solubilization, ammonia production, indole-3-acetic acid (IAA) production, biofilm formation, and tolerance to abiotic stresses, including salinity and drought. Furthermore, the P1 strain displayed strong biocontrol activity against the fungal pathogen Fusarium oxysporum f. sp. cumini, indicating its potential to mitigate biotic stress. Whole-genome sequencing generated a high-quality complete genome of 4,758,235 bp. Functional annotation showed enrichment of metabolic pathways associated with plant-microbe interactions and environmental adaptation. Further analyses using KEGG and PGPT-pred data confirmed the presence of genes associated with direct and indirect PGPT, such as nitrogen fixation, phosphate solubilization, biofilm formation, and stress tolerance. The genome also contained genes related to CAZymes, adhesion, and motility, highlighting a strong plant association, whereas the genome lacked major virulence factors and antimicrobial traits, supporting the non-pathogenic nature of the P1 strain. Overall, these findings demonstrate the potential of P1 as a promising bioinoculant candidate for sustainable agriculture in the potato sector.
Bioprospecting of plant growth-promoting bacteria enables the identification of beneficial microbial resources with significant potential for sustainable agricultural applications. In this context, strain TRQ48 was isolated from a commercial field of wheat (Triticum turgidum L. subsp. durum) located in the Yaqui Valley, Mexico, with the aim of exploring its plant growth-promoting potential. The draft genome sequence presented a genomic size of 2,777,016 bp, 32.5% G + C content, 665,763 bp N50, 2 L50, and 19 contigs. Taxonomic affiliation demonstrated that strain TRQ48 belonged to Mammaliicoccus sciuri. Genome annotation identified 2756 coding DNA sequences (CDS) distributed into 259 subsystems, highlighting CDS associated with iron acquisition and metabolism, stress response, and virulence, disease, and defense, among others. Metabolic assays reflect the strain’s capacity to produce siderophores and auxins, relating these positive traits to significantly (p ≤ 0.05) promote growth of wheat shoot length (7.09%) and root and shoot dry weight (75% and 18.43%) compared to uninoculated wheat plants. Biosafety testing indicated that the strain is susceptible to commonly used antibiotics and lacks clinically relevant resistance profiles, matching genomic analysis, which did not reveal any critical virulence factors. Thus, although the presented results show that M. sciuri TRQ48 is a promising beneficial biosafe strain, further studies are still needed to evaluate its performance under agro-ecosystems at commercial levels.
Bacillus velezensis strain H166, isolated from the apple rhizosphere, exhibits strong biocontrol efficacy against apple replant disease (ARD), a complex soilborne disease in which Fusarium oxysporum can act as an important fungal pathogen. To elucidate the underlying biocontrol mechanisms, a high-quality genome assembly of strain H166 was generated using PacBio HiFi sequencing. The genome of strain H166 consists of a single circular chromosome of 3,929,791 bp with a GC content of 46.5%, and contains 4,035 protein-coding genes, 86 tRNA genes, 27 rRNA genes, and 16 sRNA genes. Twelve secondary metabolite biosynthetic gene clusters were identified, including those associated with fengycin, surfactin, and bacillaene biosynthesis. These gene clusters are presumed to be closely associated with the biocontrol functions of this strain against Apple Replant Disease. The genome sequence provides important foundational data for further elucidating the molecular mechanisms underlying the biocontrol activity of B. velezensis strain H166.
Background: The urgent need for sustainable agricultural drives the search for effective microbial biostimulants. Cyanobacteria of the order Nostocales are promising candidates due to their nitrogen-fixing capabilities and bioactive secondary metabolites. However, the genomic potential of many soil strains from microorganism collection remains largely unexplored. Methods: We performed a targeted genomic screening of five cyanobacterial strains from the All-Russian Collection of Microorganisms (VKM): Nostoc commune VKM Al-35, Nostoc punctiforme VKM Al-37, Nostoc minutum VKM Al-168, Anabaena pirinica VKM Al-153, and Hassallia pseudoramosissima VKM Al-158. The workflow involved WGS, de novo assembly, and comparative metabolic profiling using KEGG, SEED, PLaBAse, antiSMASH, and RhizoSMASH to identify predicted plant growth-promoting (PGP) traits, biosynthetic gene clusters (BGCs), and rhizosphere competence mechanisms. Biosafety was evaluated via Comprehensive Antibiotic Resistance Database (CARD) and in silico toxomics screening. Results: High-quality genome assemblies were obtained for all strains (completeness > 99%). Functional annotation uncovered complete genetic machinery for nitrogen fixation, predicted phosphate mobilization, and phytohormone biosynthesis pathways. Comparative analysis revealed two distinct genomic strategies: a versatile support profile in Nostoc strains (expanded genomes and diverse accessory pathways) and a specialized stimulation profile in Anabaena and Hassallia strains (focused phytohormone pathways). Comprehensive CARD and antiSMASH screenings demonstrated an excellent biosafety profile, confirming the complete absence of regulated cyanotoxin clusters or acquired antibiotic resistance genes of clinical concern. Conclusions: This genome-based bioprospecting serves as a cost-effective pre-selection filter, providing a strong scientific rationale for downstream experimental validation of these strains. The presence of predicted gibberellin biosynthesis pathways and T6SS/T4SS secretion systems in H. pseudoramosissima VKM Al-158 represents a notable genomic feature among soil cyanobacteria. The identified genomic prerequisites suggest that these strains possess strong predictive potential for future development as safe biological resources for sustainable agriculture.
This study introduces L. aquatilis strain MC3 as an emerging candidate for bioinoculant development and one of the first reports for identification of L. aquatilis as multifunctional PGPR from Himalayan ecosystems.