MINERAÇÃO GÊNICA E PROSPECÇÃO DE COMPOSTOS DO METABOLISMO SECUNDÁRIO DE BACTÉRIAS ISOLADAS DE SEDIMENTOS DOS RIOS MADEIRA E SOLIMÕES

Abstract

The Amazon, with its vast river basin and diversity of ecosystems, is home to a wide variety of bacterial species, including Bacillus and Streptomyces, known for their potential in the production of molecules of biotechnological interest. With advances in next-generation sequencing (NGS) technologies and genome mining, the identification of biosynthetic gene clusters (BGCs) involved in the biosynthesis of new metabolites has become an essential approach in the discovery of bioactive compounds. In this context, the present work aimed to evaluate bacterial strains isolated from the Madeira and Solimões rivers, investigating their ability to inhibit the growth of phytopathogens, promote plant growth and produce enzymes and secondary metabolites of interest. The study involved the analysis of six bacterial strains (MAD34, MAD51, MAD1003, MAD142, SOL105 and SOL146), four of which had their genomes sequenced. The genomes had sizes ranging from 4,664,203 bp to 6,244,542 bp, with G+C content between 66.6% and 72.0% and coding regions (CDS) between 4,304 and 8,066. Comparative analyzes revealed the presence of three new species: MAD51, MAD1003 and SOL105, with dDDH values below the cutoff point of 70% (46.4% to 54.9%), also corroborated with ANI and AAI values lower than the cutoff point for new species. A pangenome analysis indicated the presence of unique genes related to the biosynthesis of antibiotics such as phenazine, metal ion binding, pyridoxine biosynthetic process, ATP binding and viral processes. Functional assays demonstrated the potential of the strains for the production of extracellular enzymes, siderophores, phosphate solubilization and production of indoleacetic acid (IAA), with emphasis on strains MAD142 (67.0 µg mL-¹) and SOL146 (70.8 µg mL-¹). In antagonism tests, the MAD34 strain presented the best results, with inhibition rates ranging from 54.70% to 90.47% against different phytopathogens. The Bacillus sp. MAD142 and Streptomyces sp. MAD51 also stood out, with protection rates above 70% and 50%, respectively, being the lowest rates collected for Stenotrophomonas SOL105. Genomic mining revealed the presence of BGCs with already described pathways for the biosynthesis of several metabolites, such as polyketides (tetracenomycin C, spore pigment and flaviolin), siderophores and non-ribosomal peptides (NRPs). The MAD34 lineage presented a total of 17 BGCs, six of which had similarity less than 50%. The MAD51 lineage exhibited 39 clusters, with 10 BGCs showing similarity above 80%. MAD1003 presented 24 clusters, nine of which had similarity above 80%. Finally, SOL105 presented a smaller number of BGCs, with a total of four clusters and a similarity of 57%. These results reinforce the importance of bioprospecting in Amazonian ecosystems for identifying new genetic resources with a focus on developing sustainable solutions for agriculture.