Diversidade microbiológica em solos do Cerrado sob cultivo de soja (Glycine max)

Abstract

In addition to the chemical and physical analyses widely used to assess soil quality, biological parameters have gained increasing prominence in recent years as a fundamental tool for a more comprehensive understanding of soil functioning. These parameters have proven relevant not only for enhancing productivity but also for reducing environmental impacts in agricultural systems. Shotgun metagenomic analysis allows for the extraction and sequencing of the total DNA from an environmental sample, enabling the quantification and identification of the microorganisms present. Within this context, studies documenting the microbial biodiversity of Cerrado soils remain scarce, as do investigations that thoroughly assess how different histories of agricultural management influence the composition and functioning of the microbial ecosystem in this biome. This study aimed to characterize the microbiological composition of two agricultural soils in the Cerrado biome, both under cultivation for approximately 30 years but with distinct management histories. Soil sampling was carried out after the completion of the 2024/25 soybean cycle, following the same protocol used on the farm for physical and chemical analyses. The samples were then sent for analysis to the company Lagbio, located in Toledo, Paraná (Brazil), using 0.25 g of homogenized soil for processing. DNA extraction was performed using the DNeasy PowerSoil Pro Kit (Qiagen), followed by metagenomic sequencing. Sequences shorter than 50 bp and with a Phred score below 20 were removed using Sickle software. Taxonomic analysis was conducted in a Linux environment using the Kraken algorithm, and data visualization was performed with the Pavian package in R software. Statistical comparisons between samples were carried out using the STAMP software. Metagenomic analysis revealed a predominantly bacterial community, with Proteobacteria and Actinobacteria as the dominant phyla. Significant differences were observed in the abundance of genera such as Bradyrhizobium, Rhizobium, Burkholderia, Nocardioides, Lechevalieria, Catelliglobosispora, Aeromicrobium, Pimelobacter, Lentzea, and Nitrososphaera. Within the Eukarya domain, a greater representation of the phyla Opisthokonta and Stramenopiles was found in both samples.