Joana Alves,Isolation and characterization of a new Thermoanaerobacter strain (strain PCO) from a syngas enriched culture
Aiming the isolation of novel syngas/CO-utilizing microorganisms, batch microbial enrichment cultures were performed. Cultures were successively transferred to basal medium containing syngas or carbon monoxide as substrate; a higher concentration of carbon monoxide was used, in both enrichment series. After more than one year growing on syngas or CO, stable enriched cultures were obtained. Serial dilutions and successive transfers of the enriched cultures were made to media containing other substrates than syngas or CO, for instance glucose, lactate, pyruvate, etc. The objective was to select the dominant organisms and to turn the isolation process faster. A new Thermoanaerobacter sp., strain PCO, was isolated from one of these syngas-degrading cultures that was enriched from a thermophilic anaerobic suspended sludge from an anaerobic reactor treating the organic fraction of municipal solid wastes. Our isolate was physiologically characterized. However, it seems that strain PCO could not convert carbon monoxide, which is one of the main components of syngas. We propose that, even though strain PCO does not convert CO, it is a carbon monoxide-tolerant microorganism.
Juliana Castro, Precipitation of hydroxyapatite in continuous-flow microsystems
Nanoparticles are of particular interest in biomedical applications since their critical size dimensions are close to cells, tissues and biological molecules. As their properties are related to their size and morphology, very good control of the reaction is required to produce particles with desired characteristics.Commonly, nanoparticles are produced by wet chemical synthesis in stirred tank, but obtaining particles with desired size and morphology can be difficult, because of the low micromixing efficiency and wide residence time.Miniaturization of synthesis systems offers many advantages, including cost saving and safer operation. Further, transfer processes, mixing of reactants and residence time are fast in miniaturized systems, which is favorable for the generation of nanosized particles with a narrow size distribution.The present work aims at the application of microsystems in the production of hydroxyapatite (HAp) Ca10(PO4)6(OH)2 nanocrystals with controlled size distribution and high biocompatibility, making them suitable for application in bone replacement.
