## 3 Results and Discussion
### Pot Essays
Even though it is well known that the low doses of the auxin IAA promote the growth of the primary root and induce lateral root development, results showed (Table 4) that ARI_A20-3 from T1 described as no IAA producer (Table 3) [50] showed a higher value in root biomass weight compared to ARI_A30-32 from T3 (described as IAA producer). This fact suggests that direct plant growth promotion can also occur by facilitating nutrients to the root through other well-known mechanisms, such as nitrogen fixation, iron acquisition by siderophores, and phosphate solubilization [13], which were reported in Table 3 as attributes for these strains, among others not reported in this work. providing better protection to the remaining hyphae or spores against hostile conditions in the rhizosphere, such as pH, desiccation, predators, and UV radiation [34; 56]. This behavior could be explained since perlite is an innocuous material with water retained inside its structure. To the best of our knowledge, no earlier studies using biofilms on this type of material utilized as an actionbacterial carrier have produced such results. Figure 4: Effects in plant growth with the biofilmed inoculant per treatments in _T. aestivum_: (**A**) height (cm); (**B**) complete spike (cm); (**C**) base spike (cm); (**D**) total biomass (g); (**E**) root biomass (cm). It has been demonstrated in earlier studies and publications that the use of biochar promotes the conservation of the viability of bacterial biomass in a range from 10% [80] to 30% [81], even if it was only included in the trials to witness the rhizosphere's interactions, so it cannot be ruled out that it could be an aid in the viability of our tests. Among the bacteria that benefited from the increase in their population were the actinobacteria of the genera _Mycolisibacteria_, _Streptosporangium_, _Actinomadura_, _Actinomidumurus_, and _Streptomyces_[82]. At the end of the pot assay, perlite from the biofilmed inoculant was recovered, fixed, and dehydrated according to the methods mentioned in the 3.2 subsection and analyzed by SEM. In all the cases, the mineral was not biofilm covered (Figure 5A), but in a close-up, it was possible to visualize vast amounts of spores between pores and surface. It was easy to distinguish the difference between spores belonging to the different strains from each treatment (Figure 5B,D), and it was possible to identify the residual components of the biofilm matrix and some spores still attached to it (Figure 5C). Spores are a resistant form of life, and they can remain in this phase for several years until the germination conditions are again suitable [65]. Therefore, their permanence in the rhizosphere between 9 and 12 years could be ensured using this type of material as a vehicle and by its conversion to spores, according to in vitro conservation studies carried out previously [79]. Although the actinobacteria were grown separately, this study provides evidence that a long-lasting reaction was carried out with the formation of a successful consortium between the different species of _Streptomyces_, as can be seen in the micrograph of Figure 5D, where the different types of spores corresponding to the different species (_S. griserorubens_, _S. flavcolus_, and _S. aureus_) can be clearly observed. Post-treatment perlites were inoculated randomly in EM agar to ensure their viability and recovery of the original microorganism (Table 5). Previously sterilized to avoid superficial microorganisms, wheat roots were analyzed for endophytic colonization using the Coombs and Franco methodology [10; 65]. The seven treatments showed positive results for endophytic colonization of the actinobacterial strains tested between 4 and 6 days. Root analysis using SEM was performed (Figure 6), and hyphae protruding from a cross-section of the root covered the surface (Figure 6A) and near the secondary roots (Figure 6B). The colonization of actinobacteria in healthy wheat tissue suggests that the host benefits in some way.