## 4 Discussions
However, the culture-dependent studies allow access to the metabolic capabilities of bacterial communities, which is later useful in testing their activity in host-microbiota interactions. From the total of the 110 families reported by [21], in our study we shared in common nine of these families and were able to recover four other families not detected in [21]: Microcococcaeae, Brevibacteriaceae, Morganellaceae and Lysobacteraceae. Therefore, for the aims of this study, which included the isolation of bacterial communities associated with _S. ramossissima_ to test their potential for PGP, our approach achieved the access tobacterial members that would actually be useful for the development of better strategies in sustainable agriculture. Culture-independent approaches indicate that Proteobacteria normally outnumber Firmicutes in the bacterial communities of the roots and in the rhizosphere of _Salicornia_ sp. ; other phyla are represented with variable abundances [21; 23]. The predominance of Firmicutes and Bacilli was more evident in the subset of isolates from both rhizosphere and endosphere of the Al site (Appendix A, Figure A3), characterized by high sediment pH and low organic matter content. The capacity to form endospores, highly resistant to unfavorable nutritional conditions, chemical stress and desiccation, may contribute to this enrichment. The highest proportion of Actinobacteria was found in the Av1 endosphere subset (Appendix A, Figure A3), which corresponds to the most saline sediments. Other authors have previously reported the association of Actinobacteria in the endosphere of _S. europaea_, particularly in plants growing in high salinity sites [21; 23; 63]. The endosphere represents a more stable and sheltered environment for symbiotic bacteria, which may underlie the preference of Actinobacteria for this plant compartment [64]. A possible relation between bacterial diversity and plant origin (wild vs. crop) was eliminated. As shown in Table 2, Av1 (crop site) rendered the highest number of OTUs (17). Four of these OTUs (belonging to genera _Kocuria_, _Virgibacillus_, and _Pseudomonas_) were found exclusively associated with plants from that site. Although _Kocuria_ was only isolated from the Av1 site, _Virgibacillus_ and _Pseudomonas_ were also isolated from Al and Tg, respectively. All other OTUs present in crop plants were also detected in wild plants from other sites. This was the case for OTUs corresponding to _Microoccus_ (also in Al), _Bacillus_ (in all other sites), _Stenotrophomonas_ (also in Tg), _Pseudomonas_ (also in Tg) and _Oceanobacillus_ (also in Av3). Therefore, we found no evidence that cultivated plants are different from wild plants in terms of culturable populations represented in the microbiome. Bulk soil microbial communities were not studied, as it would surpass the scope of this work. However, some studies found that the microbiome of bulk soil was closely related to that of the rhizosphere [65], and that rhizosphere soil was found to contain higher microbial biomass compared to bulk soil [66]. Nevertheless, in a separate study, significant differences were found between rhizosphere and bulk soil microbial composition [67]. As soil is the primary source of microbes inhabiting the rhizosphere, similarities are expected. The possibility of using rhizosphere and endosphere bacteria as biostimulants for saline agriculture or as saline-stress attenuators for salt-sensitive crops has been the motivation for many culture-dependent analyses of the microbiome of halophyte species. Salinity tolerance is a requirement of PGP bacteria used for the attenuation of saline stress. In the overall collection of isolates, 71% were able to grow at a salinity corresponding to 100 g L\({}^{-1}\) NaCl. This result demonstrates the potential of halophyte plant microbiota to harbor bacteria adapted to high salinities [11].