Salinity and Bacterial Diversity: To What Extent Does the Concentration of Salt Affect the Bacterial Community in a Saline Soil?

Abstract

In this study, the evaluation of soil characteristics was coupled with a pyrosequencing analysis of the V2-V3 16S rRNA gene region in order to investigate the bacterial community structure and diversity in the A horizon of a natural saline soil located in Sicily (Italy). The main aim of the research was to assess the organisation and diversity of microbial taxa using a spatial scale that revealed physical and chemical heterogeneity of the habitat under investigation. The results provided information on the type of distribution of different bacterial groups as a function of spatial gradients of soil salinity and pH. The analysis of bacterial 16S rRNA showed differences in bacterial composition and diversity due to a variable salt concentration in the soil. The bacterial community showed a statistically significant spatial variability. Some bacterial phyla appeared spread in the whole area, whatever the salinity gradient. It emerged therefore that a patchy saline soil can not contain just a single microbial community selected to withstand extreme osmotic phenomena, but many communities that can be variously correlated to one or more environmental parameters. Sequences have been deposited to the SRA database and can be accessed on ID Project PRJNA241061.

Soil indicators to assess the effectiveness of restoration strategies in dryland ecosystems

“…The analysis of the soil-extracted nucleic acid sequences (DNA and RNA) provides a powerful tool for the characterization of the entire microbial community. It was successfully used even in hypersaline soils of dry areas (Canfora et al, 2014(Canfora et al, , 2015. The most useful and commonly used methods are those in which small subunit RNA genes are amplified via the polymerase chain reaction (PCR) and analyzed by means of several fingerprinting techniques, such as denaturing gradient gel electrophoresis (DGGE), Terminal Restriction Fragment Length Polymorphysm (T-RFLP), or single-strand conformational polymorphism (SSCP) (Kowalchuk, 2004).…”

Spatial microbial community structure and biodiversity analysis in “extreme” hypersaline soils of a semiarid Mediterranean area

“…Soil halophiles enzymes results to be potentially useful for a variety of applications, including restoration of conditions in salt-affected soils, remediation of pollutants, industrial bio catalysis, food processing, washing, biosynthetic processes, synthesis of exopolysaccharides, compatible solutes, carotenoids (Ventosa et al, 2008). Many studies have been focused on the isolation and characterization of halophilic Bacteria and Archaea communities in saline and hypersaline soils Ventosa et al, 1998) and biotechnological applications are under investigation (Ghazanfar et al, 2010;Keshri et al, 2013;Arora et al, 2014;Tsiamis et al, 2014;Canfora et al, 2014). However, more extensive studies on the ecology, structure, diversity, and functionality of organism occurring in natural saline soils are needed.…”

Effect of Reagents Concentration on Biocementation of Tropical Residual Soil

“…The results shows that the UCS increased with an increased in the reagents concentration for both the samples treated at 0.15M and 0.25M; however, reduction in UCS value was observed for the sample treated at 0.35M. The UCS value for the sample treated at 0.35M was 94 kPa which is slightly lower than the control counterpart; a possible explanation for this observation is that, the improvement of UCS and calcite content could be affected as a result of the decrease in bacteria microbial activity due to high salinity of reagents; as high salinity impairs the nutrient and water availability for microorganism [19,20]. As a result of that, the change of nutrient and water availability with the increase of the salinity might consequently affected on the growth and microbial activity of the bacteria [21].…”