Comparison of prokaryotic community structure from Mediterranean and Atlantic saltern concentrator ponds by a metagenomic approach

Abstract

We analyzed the prokaryotic community structure of a saltern pond with 21% total salts located in Isla Cristina, Huelva, Southwest Spain, close to the Atlantic ocean coast. For this purpose, we constructed a metagenome (designated as IC21) obtained by pyrosequencing consisting of 486 Mb with an average read length of 397 bp and compared it with other metagenomic datasets obtained from ponds with 19, 33, and 37% total salts acquired from Santa Pola marine saltern, located in Alicante, East Spain, on the Mediterranean coast. Although the salinity in IC21 is closer to the pond with 19% total salts from Santa Pola saltern (designated as SS19), IC21 is more similar at higher taxonomic levels to the pond with 33% total salts from Santa Pola saltern (designated as SS33), since both are predominated by the phylum Euryarchaeota. However, there are significant differences at lower taxonomic levels where most sequences were related to the genus Halorubrum in IC21 and to Haloquadratum in SS33. Within the Bacteroidetes, the genus Psychroflexus is the most abundant in IC21 while Salinibacter dominates in SS33. Sequences related to bacteriorhodopsins and halorhodopsins correlate with the abundance of Haloquadratum in Santa Pola SS19 to SS33 and of Halorubrum in Isla Cristina IC21 dataset, respectively. Differences in composition might be attributed to local ecological conditions since IC21 showed a decrease in the number of sequences related to the synthesis of compatible solutes and in the utilization of phosphonate.

Determining virus-host interactions and glycerol metabolism profiles in geographically diverse solar salterns with metagenomics

“…The Santa Pola and Isla Cristina metagenomes have previously been taxonomically profiled through mapping of reads to 16S rRNAs obtained from the Ribosomal Database Project (Fernandez et al, 2013; Fernández et al, 2014b; Ventosa et al, 2014). These 16S rRNA profiling studies revealed that the lowest salinity saltern (SS13) contained a community of bacterial Actinobacteria and Proteobacteria and archaeal Euryarchaeota, while members of the Euryarchaeota increased in abundance with increasing salinity (Fernández et al, 2014c; Fernández et al, 2014a; Ventosa et al, 2015). Compared with the Santa Pola salterns, Cahuil and Isla Cristina salterns may be more dynamic, with more rapidly changing daily and yearly temperatures and higher rainfall (Fernández et al, 2014c).…”

“…Technical details about these microbial metagenomes are provided in Table 1. Further details about sampling are described in associated publications (Ghai et al, 2011; Fernandez et al, 2013; Fernández et al, 2014b; Fernández et al, 2014c; Plominsky et al, 2014). Chula Vista microbial metagenomes were obtained from the iMicrobe Collaborative (Hurwitz, 2014) and have been previously examined in a larger study of several aquatic biomes (Rodriguez-Brito et al, 2010).…”

Microbial diversity of hypersaline environments: a metagenomic approach

“…Interestingly, the community structure of an intermediate salinity pond (21% NaCl) located in southern Spain on the Atlantic shore was more similar at higher taxonomic levels to the Mediterranean 33% NaCl, rather than the expected 19% NaCl pond ( Figure 1). However, differences at genus level were detected between those ponds indicating that community structure is not based exclusively on salt concentrations or geographic proximity [23].…”

Diversity of extremely halophilic cultivable prokaryotes in Mediterranean, Atlantic and Pacific solar salterns: Evidence that unexplored sites constitute sources of cultivable novelty

“…The most abundant bacterial genera thriving in such environments, as revealed by both culture-dependent and -independent methods, were Salinibacter and Salicola [5,33]. In general, diversity studies have been performed mostly in brines [5,15,20,34], with very few in corresponding sediments [29].…”

“…Most of the current studies on the diversity of halophilic microorganisms in hypersaline systems have been performed by means of culture-independent molecular techniques, such as, for example, on either 16S rRNA gene diversity [20] or by metagenomic approaches [15]. Despite the fact that molecular studies describe to a great extent the taxonomic and genetic diversity of the key players in their environments, they have failed to culture living organisms that can be potentially important sources of information for biotechnological, pharmaceutical and even taxonomic purposes.…”