Bioengineering and Synthetic Microbiology

 

Previous research results

The main research topic of the group has been cyanobacterial hydrogenases and hydrogen metabolism. We investigated the transcription and expression patterns of genes related to hydrogenases, as well as the involvement of several transcriptional factors. In addition, a synthetic biology approach was introduced to solve fundamental issues related to hydrogenases function(s)/hydrogen production. Synechocystis PCC 6803 was chosen as a photoautotrophic chassis to accommodate the standardized parts and devices primarily designed for H2 production. To prepare the chassis, and since a heterologous hydrogenase was going to be introduced, genes encoding the native bidirectional hydrogenase were deleted. Furthermore, an in silico analysis of the genome was performed to identify neutral sites for the integration of synthetic parts/devices. In parallel, to achieve the microaerobic intracellular environment required for optimal hydrogenase activity, several synthetic oxygen consuming devices (OCDs) were designed.

The group is also exploring the use of exopolysaccharides(EPS)-producing cyanobacteria to remove metallic ions from polluted waters, and other forms of bioremediation. Previously, we tested the capability of several strains to remove cations from aqueous solutions, characterized the polymers produced, and identified the functional groups involved in the removal.

Together CIIMAR, we described the diversity of cyanobacterial strains isolated from the intertidal zones along the Portuguese coast. This study revealed novel diversity and that one-third of the isolates are potential nitrogen fixers, while no conventional toxin producers were detected.

 

 

Future research goals  

In the future, the group will continue to investigate the biosynthesis/ maturation of cyanobacterial hydrogenases, notably the involvement of Hyp proteins in the maturation of the uptake hydrogenase and the specificity of the endopeptidases (HoxW and HupW) in the cleavage of the C-terminal polypeptide of each large subunit precursors, the validation of the neutral sites in the genome of Synechocystis PCC 6803, and the characterization of the synthetic oxygen consuming devices in E. coli and in our photoautotrophic cyanobacterial chassis. Moreover, within the bioremediation project the genes encoding proteins involved in the last steps of EPS production and the physiological/environmental conditions promoting their production and export will be characterized, and small scale metal bioremoval assays will be performed. In the isolated marine cyanobacterial strains, no genes involved in the production of conventional freshwater toxins were found. However, cell extracts were toxic to invertebrates suggesting the presence of other compounds, which are currently being investigated.

 

Cyanofactory

 

Selected references

Pinto, F., Pacheco, C.C., Ferreira, D., Moradas-Ferreira, P. & Tamagnini P. 2012. Selection of suitable reference genes for RT-qPCR analyses in cyanobacteria. PLoS One 7: e34983.

Brito, Â., Ramos, V., Seabra, R., Santos, A., Santos, C.L., Lopo, M., Ferreira, S., Martins, A., Mota, R., Frazão, B., Martins, R., Vasconcelos, V.M. & Tamagnini, P. 2012. Culture-dependent characterization of cyanobacteria diversity in the intertidal zones of the Portuguese coast: a polyphasic study. Syst. Appl. Microbiol. 35: 110-112.

Pinto, F., van Elburg, K.A., Pacheco, C.C., Lopo, M., Noirel, J., Montagud, A., Urchueguía, J.F., Wright, P.C. & Tamagnini P. 2012. Construction of a chassis for hydrogen production: physiological and molecular characterization of a Synechocystis sp. PCC 6803 mutant lacking a functional bidirectional hydrogenase. Microbiology 158: 448-464.

Pereira, S.B., Ow, S.Y., Barrios-Llerena, M.E., Wright, P.C., Moradas-Ferreira, P. & Tamagnini P. 2011. iTRAQ-based quantitative proteomic analysis of Gloeothece sp. PCC 6909: Comparison with its sheathless mutant and adaptations to nitrate deficiency and sulfur limitation. J. Proteomics 75: 270-283.

Pereira, S., Zille, A., Micheletti, E., Moradas-Ferreira, P., De Philippis, R. & Tamagnini, P. 2009. Complexity of cyanobacterial exopolysaccharides: composition, structures, inducing factors and genes putatively involved in their biosynthesis and assembly. FEMS Microbiol. Rev. 33: 917-941.

Tamagnini, P., Leitão, E., Oliveira, P., Ferreira, D., Pinto, F., Harris, D.J., Heidorn, T. & Lindblad, P. 2007. Cyanobacterial hydrogenases. Diversity, Regulation and Applications. FEMS Microbiol. Rev. 31: 692-720.

 

 

 

Group Leader
255.jpeg
pmtamagn@ibmc.up.pt
People
Researchers

Gales, Luís
lgales@ibmc.up.pt

Pacheco, Catarina
cclopes@ibmc.up.pt

Pereira, Sara Isabel
sarap@ibmc.up.pt

Santos, Arlete
arsantos@ibmc.up.pt

PosDocs

Albuquerque, Pedro
pedro.albuquerque@i3s.up.pt

Brito, Ângela
ambrito@ibmc.up.pt

Mendes, Marta
mvm@ibmc.up.pt

Nunes de Oliveira, Paulo
paulo.oliveira@ibmc.up.pt

Phd Students

Barbosa de Oliveira, Rute
rute.oliveira@ibmc.up.pt

Ferreira, Eunice
eunice.ferreira@ibmc.up.pt

Flores, Carlos
carlos.flores@ibmc.up.pt

Fonseca Santos, Marina
marina.santos@ibmc.up.pt

Marques, Filipe
filipecastromarques@gmail.com

Mota, Rita Vasconcelos
rita.mota@ibmc.up.pt

MSc Students

Costa, Bruna
bruna.costa@i3s.up.pt

Patrícia Pedrosa Martins, Teresa
teresa.martins@i3s.up.pt

Trainees

Pedro Santos Leite, José
jose.leite@ibmc.up.pt

Technicians

Pinho, Maria Helena
maria.pinho@ibmc.up.pt

Collaborators

Miguel Bastos Pires, Leandro
up201505561@fc.up.pt

Soecker, Tim
tim.soecker@googlemail.com


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