Molecular characterization of bacterial populations of different soils

Abstract

Until recently, few studies were carried out in Brazil about diversity of bacterial soil communities. Aiming to characterize the bacterial population in the soil through 16S rRNA analysis, two types of soil have been analyzed: one of them characterized by intensive use where tomato, beans and corn were cultivated (CS); the other analyzed soil was under forest (FS), unchanged by man; both located in Guaíra, São Paulo State, Brazil. Using specific primers, 16S rRNA genes from metagenomic DNA in both soils were amplified by PCR, amplicons were cloned and 139 clones from two libraries were partially sequenced. The use of 16S rRNA analysis allowed identification of several bacterial populations in the soil belonging to the following phyla: Acidobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria Verrucomicrobia in addition to the others that were not classified, beyond Archaea domain. Differences between FS and CS libraries were observed in size phyla. A larger number of phyla and, consequently, a greater bacterial diversity were found in the under-forest soil. These data were confirmed by the analyses of genetic diversity that have been carried out. The characterization of bacterial communities of soil has made its contribution by providing facts for further studies on the dynamics of bacterial populations in different soil conditions in Brazil.

Changes in land use alter the structure of bacterial communities in Western Amazon soils

“…This is true for tropical regions in general, as few studies have focused on belowground biodiversity (Swift et al, 1998), especially when compared to the attention aboveground diversity has received. Some surveys in the Amazon and other tropical environments report the composition of soil bacterial communities and the effect of land use and forest recovery on their phylogenetic and functional diversity (Borneman and Triplett, 1997;Yin et al, 2000;da Silveira et al, 2006;Pereira et al, 2006;Quirino et al, 2009), but factors possibly causing these changes remain to be determined.…”

Microbial community structure and chemical composition from dark earth in a native archaeological site of the lower Amazon

“…Microorganisms are a component of these ecosystems (Pereira et al, 2006). Microorganisms are involved in biodegradation, decomposition and mineralization, and inorganic nutrient cycling in soils.…”

“…Therefore, the Brazilian government provides financial support for research. The application of molecular techniques in the microbial diversity and structure analysis of these communities has been used previously (Bossio et al, 2005;Pereira et al, 2006;Castro et al, 2008;Taketani et al, 2013;Brossi et al, 2014). The molecular approaches have been proven to be powerful tools in providing an inventory of the microbial diversity in environmental samples (Ascher et al, 2010;Silva et al, 2012).…”

Isolation and Molecular Characterization of Elite Indigenous <i>Rhizobia</i> Nodulating <i>Phaseolus</i> bean (<i>Phaseolus vulgaris</i> L.)

“…It is among the most important sources of dietary protein to human [11]. Its production in tropics and subtropics regions is deterred by poor soil fertility [9] [12]- [15]. This is due to the fact that this crop is mostly grown by the resource-poor small scale farmers [9] [16] who are not able to purchase expensive inorganic fertilizers.…”