Production and covalent immobilisation of the recombinant bacterial carbonic anhydrase (SspCA) onto magnetic nanoparticles

Carbonic anhydrases (CAs; EC 4.2.1.1) are metalloenzymes with a pivotal potential role in the biomimetic CO2 capture process (CCP) because these biocatalysts catalyse the simple but physiologically crucial reaction of carbon dioxide hydration to bicarbonate and protons in all life kingdoms. The CAs are among the fastest known enzymes, with kcat values of up to 106 s!1 for some members of the superfamily, providing thus advantages when compared with other CCP methods, as they are specific for CO2. Thermostable CAs might be used in CCP technology because of their ability to perform catalysis in operatively hard conditions, typical of the industrial processes. Moreover, the improvement of the enzyme stability and its reuse are important for lowering the costs. These aspects can be overcome by immobilising the enzyme on a specific support. We report in this article that the recombinant thermostable SspCA (a-CA) from the thermophilic bacterium Sulfurihydrogenibium yellowstonense can been heterologously produced by a highdensity fermentation of Escherichia coli cultures, and covalently immobilised onto the surface of magnetic Fe3O4 nanoparticles (MNP) via carbodiimide activation reactions. Our results demonstrate that using a benchtop bioprocess station and strategies for optimising the bacterial growth, it is possible to produce at low cost a large amount SspCA. Furthermore, the enzyme stability and storage greatly increased through the immobilisation, as SspCA bound to MNP could be recovered from the reaction mixture by simply using a magnet or an electromagnetic field, due to the strong ferromagnetic properties of Fe3O4

Harmonic technology versus neodymium-doped yttrium aluminium garnet laser and electrocautery for lung metastasectomy: An experimental study

We compared the efficacy of non-anatomical lung resections with that of three other techniques: monopolar electrocautery; neodymium-doped yttrium aluminium garnet laser and harmonic technology. We hypothesized that the thermal damage with harmonic technology could be reduced because of the lower temperatures generated by harmonic technology compared with that of other devices.OBJECTIVES We compared the efficacy of non-anatomical lung resections with that of three other techniques: monopolar electrocautery; neodymium-doped yttrium aluminium garnet laser and harmonic technology. We hypothesized that the thermal damage with harmonic technology could be reduced because of the lower temperatures generated by harmonic technology compared with that of other devices. METHODS Initial studies were performed in 13 isolated pig lungs for each group. A 1.5-cm capsule was inserted within the lung to mimic a tumour and a total of 25 non-anatomical resections were performed with each device. The damage of the resected lung surface and of the tumour border were evaluated according to the colour (ranging from 0 - pink colour to 4 - black colour), histological (ranging from Score 0 - no changes to Score 3 - presence of necrotic tissue) and radiological (ranging from Score 0 - isointense T2 signal at magnetic resonance imaging to Score 3 - hyperintense T2 signal) criteria. A total of seven non-anatomical resections with harmonic technology were also performed in two live pigs to assess if ex vivo results could be reproducible in live pigs with particular attention to haemostatic and air-tightness properties. RESULTS In the ex vivo lung, there was a statistical significant difference between depth of thermal damage (P < 0.0001) in electrocautery (1.3 [1.2-1.4]), laser (0.9 [0.6-0.9]) and harmonic (0.4 [0.3-0.5]) groups. Electrocautery had a higher depth of thermal damage compared with that of the laser (P = 0.01) and harmonic groups (P = 0.0005). The harmonic group had a less depth of thermal damage than that of the laser group (P = 0.01). Also, histological damages of tumour borders (P < 0.001) and resected lung surface (P < 0.001), radiological damage of tumour borders (P < 0.001) and resected lung surface (P < 0.001) and colour changes (P < 0.001) were statistically different between three study groups. Resections of in vivo pig lungs showed no bleeding; 2 of 7 cases of low air leaks were found; however, they ceased by sealing lung parenchyma with harmonic technology. CONCLUSIONS Our experimental data support the resections performed with the use of harmonic technology. The lack of severe tissue alterations could favour healing of parenchyma, assure air tightness and preserve functional lung parenchyma. However, randomized controlled studies are needed in an in vivo model to corroborate our findings

Accrescimento di Mytilus galloprovincialis mediante alimentazione con microalghe generate da refluiGrowth of Mytilus galloprovincialis through feeding based on wastewater-cultivated microalgae

The aim of this study was to evaluate the growth of juvenile Mytilus galloprovincialis fed with microalgae produced by wastewater, as well as to validate the nutritional quality of this production. The microalgae (Tetraselmis suecica and Isocrysis galbana) were produced with a culture medium obtained by the outflow of a rotating biological contactor (RBC) installed in a pilot aquaculture wastewater plant. The RBC system allows a suitable wastewater treatment to transform waste in a medium for algae biomass production. The cultivated algae can be used as a valuable feed (additive or substitutive) for mussel growth in marine aquaculture. The molluscs growth did not shown significant differences between control and experimental group fed with wastewater-cultivated microalgae

Microalgae from aquaculture wastewater as food for mussels in Recirculating Aquaculture System

The aim of this experimentation was the evaluation of the nutritional quality of the micro algae produced with the outflow medium of a rotating biological contactors (RBCs)from aquaculture wastewater and used for growth of mussel Mytilus galloprovincialis specimen in RAS (Recirculating Aquaculture System). Nutritional parameters did not show any significant differences between algae cultured by classic methods (Guillard medium) and those produced with the RCBs treated waste. In addition, the molluscs growth, (soft tissue wet weight), did not show significant difference between the controls and the experimental groups fed with algae from the RBCs outflow. The system RCBs allows a meaningful biomass production from the biotechnological waste treatment, and also revealed an available procedure for the mussel growth to be use as an additive or substitutive live food in aquaculture fish diet