Diversidade de bactérias do ciclo do nitrogênio em amostras de solo sob diferentes manejos agrícolas e mata nativa

Abstract

The nitrogen cycle is a cycle composed of successions of metabolic processes carried out by various bacteria of free-life and symbionte capable of transforming gaseous nitrogen (N2) into assimilable forms by plants. The biological fixation of nitrogen is the main responsible for meeting the nitrogen needs of the plants. This work aimed to evaluate the diversity of these bacteria belonging to the nitrogen cycle in four samples of soil under different agricultural management and sample of native forest soil, through bioinformatics tools for analysis of total metagenomic DNA. Solo samples were collected in the region of the Municipality of Dourados (MS), at EMBRAPA Agropecuária West farm, a total DNA sequencing was done through the WGS sequencing technology (WHOLE GENOME SHOTGUN) by the ILLUMINA HISEQ 2500 platform generating a total of 460.236 ORFs, data for bioinformatics analyzes used in this work were obtained in a previous job. The data obtained by the sequencing of soil samples were exported to the MG-RAST platform and comparisons were made with Refseq databases for and KO (KEGG Orthology), the resulting sequences were analyzed in the Stamp program. The analyzes were made from the main genres of bacteria present in the cycle of nitrogen being them the genres azorhizobium, bradyrhizobium, mesorhizobium, methylobacterium, nitrobacter, rhizobium and sinrhizobium. With the results generated by the MG-RAST, the occurrence of all the bacteria analyzed in all soil samples, in total were 43561 sequences found being 2083 sequences related to the gender Azorhizobium, 17368 referring to the genus Bradyrhizobium, 3050 referring to the genus Mesorhizobium, 8616 referring to the genus Methylobacterium, 5881 concerning the genus Nitrobacter, 3480 referring to the genus, Rhizobium and 3079 referring to the Sinorhizobium genus. A total of 20 species of bacteria belonging to the genera analyzed, the species Bradyrhizobium japonicum appeared with a greater proportion in the samples analyzed. We identified 21 sequences referring to enzymes belonging to the nitrogen cycle, these results show that there is a great diversity of nitrogen cycle bacteria in agricultural management and native forest.