## 3 Results
### Rhizosphere and Endosphere Bacterial Isolates  
In total, 120 salt tolerant bacterial isolates were obtained from the rhizosphere and endosphere of _S. ramossissima_ derived from the sampled sites at Portugal's coast. The similarities of 16S rRNA sequences with reference sequences in NCBI ranged from 97 to 100%, allowing the taxonomic assignment of all isolates. Overall, bacteria isolated from the endosphere were more phylogenetically diverse than isolates from the rhizosphere of _S. ramossissima_ (Appendix A, Figure A2). This was true for all the sampling sites (Appendix A, Figure A3). The most abundant taxonomic class identified was Bacilli, with the Bacillales order as the most representative for both endosphere and rhizosphere sources. Isolates belonging to Gammaproteobacteria were also common in the rhizosphere and endosphere \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Sites**} & \multicolumn{8}{c}{**Sediment**} & \multicolumn{8}{c}{**Pore Water**} \\ \cline{2-13}  & **pHw \({}^{\text{a}}\)** & **pHca \({}^{\text{b}}\)** & **ECe** & **SOM** & **Na** & **Mg** & **K** & **Ca** & & & **ECw** \\  & **pHw \({}^{\text{a}}\)** & **pHca \({}^{\text{b}}\)** & **(dS m\({}^{-1}\))** & **(dS m\({}^{-1}\))** & **(dS m\({}^{-1}\))** & **(dS m\({}^{-1}\))** & **(dS m\({}^{-1}\))** & **(dS m\({}^{-1}\))** & **(dS m\({}^{-1}\))** \\ \hline
**Av1** & 7.3 & 7.2 & 129 & 6.08 & 972 & 139 & 47 & 176 & 13.3 & 17 & 7.3 & 113.1 \\
**Av2** & 7.5 & 7.4 & 177 & 4.26 & 994 & 355 & 84 & 90 & 10.5 & 14 & 7 & 128.5 \\
**Av3** & 6.7 & 6.7 & 56 & 7.22 & 711 & 109 & 43 & 84 & 12 & 16 & 7.6 & 68.5 \\
**Tg** & 7.2 & 7.2 & 39 & 2.55 & 385 & 70 & 31 & 89 & 7.4 & 10 & 6.8 & 47.1 \\
**Al** & 8.1 & 8.0 & 89 & 2.21 & 476 & 132 & 19 & 3016 & 2.3 & 2 & 7.2 & 108.1 \\ \hline \hline \end{tabular}  
* pH of sediment in water suspension; \({}^{\text{b}}\) pH of sediment in CaCl\({}_{2}\) suspension; \({}^{\text{c}}\) electric conductivity of the sediment saturation extract;
* sediment organic matter; \({}^{\text{c}}\) sodium adsorption ratio; \({}^{\text{f}}\) exchangeable sodium percentage; \({}^{\text{g}}\) pH of pore water; \({}^{\text{h}}\) electrical conductivity of pore water.  
\end{table} 
Table 1: Physico-chemical properties of sediments and pore water at Ria de Aveiro (Av), Tagus estuary (Tg) and Almargem (Al) sulfarmashes. compartments, but members of the Alphaproteobacteria and Actinobacteria taxonomic classes were only recovered from the endosphere (Appendix A, Figure A2). In particular, Bacilli was the only class identified in the rhizosphere of the most saline places (Av2, Av1, Al and Av3), while the rhizosphere of the less saline area (Tg) was more diverse, representing bacteria from three different taxonomic classes. Gammaproteobacteria were represented mainly in the endosphere of all the subsets, except for Al, but also in the rhizosphere of the less saline places (Av3 and Tg). Although in the minority, Actinobacteria were found in the endosphere of all sampling sites, with the exception of Av2 and Tg (Appendix A, Figure A3). _Bacillus_ was the dominant genus in the total collection (41%), followed by _Staphylococcus_ (8%), which, however, was not represented in the subset of isolates from Tg (Figure 1). Some other halotolerant genera were particularly enriched in specific sites, such as _Psychrobacter_ in Tg, _Providencia_ in Av3 and _Halomonas_ in Av2 (Figure 1). The 120 partial 16S rRNA sequences (approx. 900 pb) corresponding to the 120 isolates were aligned and grouped in 41 different OTUs. The resulting OTU table containing the abundance of OTUs across the sampling sites was used to calculate the Shannon diversity and Pielou evenness indices. The highest richness (number of OTUs), evenness and diversity (Shannon) were found for the subset of isolates corresponding to Av1, and the lowest richness, diversity and evenness was found for the Al site (Table 2).