## Results and Discussion
### Biotreatment of Support Materials
Ten strains were selected as the predominant morphotypes and they were identified as _Microoccus aloeverae_, _Kocurigugangalliensis_, _Brevibacterium casei_, _Gulosibacter miniatvorax_, _Citricoccus laciaensis_, _Microbacterium_ sp., _Microbacterium phyllosphaerae_, _Brevundimonas vesicularis_, _Brevundimonas diminuta_ and _Microbacterium paraoxydans_. It is worth noting that some of these microorganisms, such as _Brevundimonas_, _Gulosibacter_ or _Kocuria_, have been previously isolated from environments contaminated with hydrocarbons and they have also been described as biosurfactant producers. Biosurfactants increase the bioavailability of hydrocarbons and facilitate their biodegradation, so it is an important characteristic of the hydrocarbon-degrading microorganisms [48; 49; 50]. Accordingly, the isolated strains could be useful for building bacterial consortia capable of degrading complex mixtures of hydrocarbons and support the potential degradation capacity of biofilm formed in bioreactors [48; 49; 50]. Further, to determine the relationship between the biological and chemical parameters a multidimensional scaling (MDS) was performed to analyze the distribution of treatments (Figure 7). The initial conditions of each treatment were clustered in group I; this group showed a high distance from group II corresponding to the data of treated water and from group III, which includes the data of hydrocarbon concentrations absorbed on the carriers. The biological and chemical parameters used to compare the efficiency of polluted water treatments (group II) did not show a statistically significant difference among the treatments at the end of the assays. However, hydrocarbons adsorbed on carriers during the carrier biotreatment showed a high variability and dispersion of data sets (group III). Based on the results obtained from the non-metric multidimensional scaling analysis (MSD) correlation analysis, principal component analysis (PCA) was used to explain the variability observed in the samples of support materials from each treatment (Figure 8). Figure 6: SEM images. General view of bacteria adhering to (**A**) Pad SentecTM structure (**B**) CorkSorbTM 01025 structure and (**C**) Barrier SentecTM structure during the carrier biotreatment phase after four months. The percentages of TPH and branched alkanes degradation were found to be the major factors explaining the variability in each one of the support material. The plot shows the clear link between the Pad SentenceTM carrier and the TPH degradation rate during the assay (circle II). On the other hand, the high degradation of the branched fraction was associated with the CorkSorbTM 01025 carrier after 120 days of treatment (circle I). The difference between the CorkSorbTM 01025 and Pad SentenceTM carriers depends on the adsorption capacity and the accessibility to the carrier surface. In the case of CorkSorbTM 01025, the hydrophobic character is mainly responsible for the process of sorption of the hydrocarbon fractions, especially the  
Figure 8: Principal component analysis (PCA) results for Pad SentenceTM, CorkSorbTM 01025 and Barrier SentenceTM samples from each treatment, as well as biological and chemical data along straight lines for degradation of TPH, hydrocarbon fraction concentrations and indigenous microbiota. Figure 7: Optimal two dimensional configurations computed by multidimensional scaling (MDS) correlation of the water samples from the bioreactors and support material samples from each treatment. branched ones and is due to its main components (lignin and polysaccharides) in the primary wall, however, the presence of cork waves (aliphatic extracts) inside it hinders the absorption of other fractions. For this reason, the presence of biomass increases the accessibility of these contaminates through the cork cell wall [51]. On the other hand, the Pad Sentec(tm) is a web of individual fibers that contains small pores that facilitate the transport of contaminated water and also retains the particles after absorption.