S. Martins-Dias

A quantitative proteomic approach to highlight Phragmites sp. adaptation mechanisms to chemical stress induced by a textile dyeing pollutant.

Phragmites sp. is present worldwide in treatment wetlands though the mechanisms involved in the phytoremediation remain unclear. In this study a quantitative proteomic approach was used to study the prompt response and adaptation of Phragmites to the textile dyeing pollutant, Acid Orange 7 (AO7). Previously, it was demonstrated that AO7 could be successfully removed from wastewater and mineralized in a constructed wetland planted with Phragmites sp. This azo dye is readily taken up by roots and transported to the plant aerial part by the xylem. Phragmites leaf samples were collected from a pilot scale vertical flow constructed wetland after 0.25, 3.25 and 24.25h exposure to AO7 (400mgL-1) immediately after a watering cycle used as control. Leaf soluble protein extraction yielded an average of 1560 proteins in a broad pI range (pH3-10) by two-dimensional gel electrophoresis. A time course comparative analysis of leaf proteome revealed that 40 proteins had a differential abundance compared to control (p<0.05) within a 3.25h period. After 24.25h in contact with AO7, leaf proteome was similar to control. Adaptation to AO7 involved proteins related with cellular signalling (calreticulin, Ras-related protein Rab11D and 20S proteasome), energy production and conversion (adenosine triphosphate synthase beta subunit) carbohydrate transport and metabolism (phosphoglucose isomerase, fructose-bisphosphate aldolase, monodehydroascorbate reductase, frutockinase-1 and Hypothetical protein POPTR_0003s12000g and the Uncharacterized protein LOC100272772) and photosynthesis (sedoheptulose-1,7-bisphosphatase and ferredoxin-NADP+ reductase). Therefore, the quantitative proteomic approach used in this work indicates that mechanisms associated with stress cell signalling, energy production, carbohydrate transport and metabolism as well as proteins related with photosynthesis are key players in the initial chemical stress response in the phytoremediation process of AO7.

Modelling of olive mill wastewater characteristics

A synthesis of the analytical work carried out on the characterisation of Olive Mill Wastewater (OMW) is given, covering articles published over the last 30 years, being excluded all data that didnt account phenol quantification. Due to the wide range of the data on OMW characterisation found in the literature, results on Chemical Oxygen Demand, Biochemical Oxygen Demand, Total Solids and Volatile Solids are summarised and correlations between them and with polyphenol content are sought. The aim of this work is to use the modelling of the analytical parameters to define working limits, in order to be able to predict and monitor successfully an OMW treatment. Scale-up from previously published data will be considered, trying to overcome the case-by-case studies found in the literature. Thls modelling also contributes to obtain a good experimental performance with a specific OMW. Portuguese OMW characterisation for the aforementioned parameters is carried out, as well as the validation of the correlations found for the parameters in the literature.