## 3 Results
### Overexpression in Secondary Metabolism
These conditions showed a higher expression of macB gene compared to macA, suggesting the importance of macB and the downstream regulator in orfamide synthesis, as observed by [PERSON] et al. [60] where in mutants with deletion of LuxR2, the expression of macB was weaker than macA, avoiding the production of ordamides. Regions 7 and 9 were identified as RiPP-like metabolites, according to antiSMASH \"Other unspecified ribosomally synthesized and post-translationally modified peptide product (RiPP) cluster\". This means that these gene clusters might induce the synthesis of a secondary metabolite, but none of the described compounds can be assigned to these genetic mechanisms. Genome mining and the recent discovery of RiPPs has awakened interest [61]. Solid culture in both phases of growth was the condition that differentially expressed the suggested core genes, which were identified as \"hypothetical protein\" in both gene clusters. A possible NRPS-like metabolite predicted in region 13 didn't match with any described metabolite. The core gene appeared to be differentially expressed under SGS condition and, although it was overexpressed in other conditions, only in this dataset was the overexpression of contiguous genes observed, with the presence of two transcriptional regulator tetR-like genes upstream and downstream of core biosynthetic gene and pyrrolquinoline quinone-like enzyme (PQQ), synthesized by only a few bacteria and with possible relevance in plant growth-promoting bacteria [62]. Though there was no connection of this gene cluster with any described biosynthetic processes in the closest sequences from _P. juntendi, P. putida_, and _P. fuccosquigiae_, ranging from 88.7% to 81.2% of similarity, the core gene was shown to be certainly related with siderophore biosynthesis from _Pseudomonas_ sp. R4-34-07, a plant-beneficial bacterium [63], with 63% of similarity. Other, more distant relatives were _Vibrio spartinae_, isolated from salt-marsh plant [64], and several strains of the species _Xenorhabditis bovienii_, including the entomopathogenic strain SS-2004 [65]. The homoserine lactone gene cluster, found in region 14, has no described metabolite associated, but as a well-known auto-inducer for Gram-negative bacteria it could have function in the production of antibiotics, pathogenicity, virulence, pigment formation, or sporulation [66]. The core gene was overexpressed in every analyzed condition, with high incidence in GLY and SGE. Finally, two separated gene clusters involved, apparently, in the pyoverdine production, with a self-made nexus gene cluster, not predicted by antiSMASH, were in regions 17 and 18, where core biosynthetic genes were identified as pvdL and pvdIJD, respectively. Pyoverdine is an essential metabolite produced by the named \"Fluorescent Pseudomonas\" bacteria, where _P. aeruginosa_, _P. fluorescens_, _P. putida_ and _P. syringae_ are the most important species [67]. This siderophore biogenesis begins after pvdL, pvdI, and pvdD expression, depending on the strain [68; 69; 70; 71]. Lacking iron in liquid cultured conditions showed a substantial rising of expression of mentioned and auxiliary genes, being differentially expressed in GYS dataset. Within this condition, pvdL and pvdD were the core genes significantly overexpressed, which are part of the \"siderosome\", the enzymatic complex located in cytoplasm where the acylated ferribactin precursor of pyoverdine is synthesized. Once this metabolite is generated, it is exported to the periplasm through PvdE protein and deacylated and oxidized to dihydropyverdine by PvdQ (out of pyoverdine biosynthesis gene cluster) and PvdP, respectively. PvdP is responsible for the complete fluorophore formation [72] and along with PvdO they are the enzymes involved in complete oxidation of dihydropyverdine. In fact, PvdO is the cause of the final oxidation, without which pyoverdine formation is not possible [73].