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Research groups

Cell biology and Biotechnology

Dr Belén Floriano. UPO
Gene regulation in bacteria of environmental interest
Dr Belén Floriano. UPO
Researcher associated to Dr Eduardo Santero Santurino. UPO

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Summary

Current position at CABD: Associated researcher
Current position at UPO: Full professor

Previous scientific experience:
Molecular biology of filamentous cyanobacteria (IBVF-CSIC)
Antibiotic production regulation in Streptomyces (JIC-BBSRC)
Bacteriocin production by lactic acid bacteria (IG-CSIC)

Projects:

Regulation of biodegradation pathways for aromatic compounds in Gram positive bacteria of environmental interest
Rhodococcus sp strain TFB is a versatile gram positive bacterium able to grow using different aromatic compounds (like tetralin, naphthalene, phthalate, etc.) as carbon and energy sources transforming them to CO2 and water. Since this strain is refractory to genetic analysis, we have made use of a proteomic approach to characterize the metabolic pathways involved in the catabolism of such compounds by analyzing differentially induced proteins in 2D-DIGE gels. Identification of those proteins allowed us to clone and sequence the corresponding genes to study their expression.
Diverse regulatory mechanisms seem to be operating at the same time in this bacterium to control the expression of catabolic genes in response to the presence of the right signal in the medium. Using different approaches, we are characterizing the promoters that drive the transcription of the catabolic genes and the proteins involved in such control in TFB.



 
 
Molecular mechanism of thn genes regulation in Sphingopyxis granuli strain TFA
The success of a bacterium in the environment depends not only on its metabolic versatility but on the regulatory mechanisms that ensure the expression of the catabolic pathways when is needed. S. granuli strain TFA is a gram negative bacterium able to grow on tetralin (a compound with an alicyclic and an aromatic ring) as carbon and energy sources. Catabolic thn genes are regulated at two different levels: specific induction by tetralin and catabolite repression, a global gene expression control that assures the absence of thn genes expression when a preferential carbon source is present in the medium. Specific tetralin induction relies on a transcriptional regulator (ThnR) whose activity is modulated by a system that “talks” to the metabolic pathway at the same time (see the work of the collaborator Dr Francisca Reyes). In this project we are studying the molecular mechanism by which ThnR acts as transcriptional activator and identifying the elements involved in catabolite repression in TFA.

Identification and characterization of sRNA in 
Sphingopyxis granuli strain TFA
The main objective is the characterisation of sRNAs-mediated regulation in strain TFA and the role of the Hfq protein in this regulation. Posttranscriptional gene regulation by small non-coding RNAs is a phenomenon whose relevance in bacterial physiology is increasingly acknowledged. In addition, the gene coding for their protein partner Hfq in TFA has an unusual structure.

Metabolic reconstruction of Sphingopyxis granuli strain TFA
Metabolic reconstruction of strain TFA is in progress through integration of information coming from genomic functional annotation (García-Romero et al, 2016), data from –omic analyses such as proteomic or transcriptomic analyses, together with the available biological information for this bacterium. This metabolic model is transformed into computational models that allow cuantitative prediction of the different phenotypic states, in terms of metabolic fluxes through the single reactions.