Microbial characterization of Arachis pintoi and its silages at different fermentation periods.

The microbial community present in forage peanut, a tropical legume, and its silages are unknown. For this reason, we used the Ion Torrent platform to study the bacterial community present in this legume during silage fermentation. Forage peanut was harvested at the start of flowering with a backpack mower and was chopped with a stationary ensilage cutter and then ensiled in bags measuring 25.40 cm × 35.56 cm, in triplicate. The bags were opened after 1, 3, 7, 14, 28 and 56 days of fermentation. Primers targeting the 16S rDNA gene were used, and the PCR products were used in library preparation and sequencing using the Ion Torrent platform. In total, 721,837 sequences were obtained and processed using the program MOTHUR v.23.0. The sequencing result revealed that the genus Weissella was present at the different periods of fermentation of peanut silage in greater amounts than the other genera (Bacillus, Rummeliibacillus, Enterococcus, Lactobacillus, Pediococcus). The six libraries constructed reached high coverage value (0.999). Comparison of the number of operational taxonomic units (OTUs) between the forage crop and the silages with 14 and 56 days of fermentation revealed that some sequences were exclusive to the plant and others to fermentation periods. The silage with 28 days of fermentation remained distant from the other fermentation periods in regard to microbial diversity. Knowledge of the diversity of different bacterial genera through sequence analysis can guide bioprospecting studies.