Effects of Ca2+ Ions on the Localized Corrosion of Carbon Steel Influence of the Associated Anion

The corrosion rate of carbon steel under the attack of electrolytic mediums saturated by CO2 at a working temperature of 65 °C under dynamic conditions is studied in this paper. The effect of Ca2+ ions on corrosion rates and their dependency on the associated anion (Cl− or CO32−) with respect to the Ca2+ cation and Na+ are also assessed. A potentiostat/galvanostat associated with a rotor stator in an AISI 1040 steel-ring configuration, rotating at 600 rpm, was used. A linear polarization-resistance technique was applied to calculate the corrosion rate. It is found that the corrosion rate depends not only on the presence of Ca2+, but also on the salt anion added to the electrolytic medium. There was a strong inhibitory effect of the corrosion in the presence of Ca2+ in chloride-free mediums because of an ankerite deposition with a lower solubility compared to siderite. Moreover, it was observed that, even if the corrosion rate increased together with the Cl− concentration, its value depended on the cation introducing the anion. It was higher when Cl− was associated with Na+ compared to when it was associated with Ca2+. We found the following decreasing order in the carbon steel corrosion rate: 2% NaCl + 1380 ppm CaCl2 > 2% NaCl > 2% NaCl + 1360 ppm Na2CO3 > 2% NaCl + 1.25 g/L CaCO3 > 1450 ppm of NaCl > 1380 ppm CaCl2 > 1360 ppm Na2CO3 > 500 ppm CaCl2 > 424 ppm Na2CO3 >> 1.250 g/L CaCO3.Fil: Acosta, Verónnica Viviana. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bianchi, Gustavo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

Heterologous expression of a global transcriptional regulatory protein in a non-oleaginous Rhodococcus Erythropolis strain to improve lipid production

Lipid accumulation is a well-studied process that occurs in many bacteria, such as those of the genus Rhodococcus, due its biotechnological applications. In a previous study, we identified and characterized a pleiotropic transcriptional regulator called NlpR (Nitrogen Lipid Regulator) that simultaneously modulates carbon and nitrogen metabolisms in the oleaginous R. jostii strain RHA1 in response to nitrogen limitation. In this study we analyzed the effect of the heterologous expression of NlpR from R. jostii RHA1 on lipid accumulation in the non-oleaginous strain; Rhodococcus erythropolis ATCC 15960.Fil: Gallegos, Andrea Laura. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; Argentina. Universidad Nacional de la Patagonia. Facultad de Ingeniería. Sede Puerto Madryn; ArgentinaFil: Hernández, Martín Alejandro. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; Argentina. Universidad Nacional de la Patagonia. Facultad de Ingeniería. Sede Puerto Madryn; ArgentinaFil: Acosta, Verónnica Viviana. Universidad Nacional de la Patagonia Austral. Centro de Investigaciones y Transferencia Golfo San Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia Golfo San Jorge. Universidad Nacional de la Patagonia "San Juan Bosco". Centro de Investigaciones y Transferencia Golfo San Jorge; Argentina. Universidad Nacional de la Patagonia. Facultad de Ingeniería. Sede Puerto Madryn; ArgentinaFil: Silva, Roxana Alejandra. Universidad Nacional de la Patagonia Austral. Centro de Investigaciones y Transferencia Golfo San Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia Golfo San Jorge. Universidad Nacional de la Patagonia "San Juan Bosco". Centro de Investigaciones y Transferencia Golfo San Jorge; Argentina. Universidad Nacional de la Patagonia. Facultad de Ingeniería. Sede Puerto Madryn; ArgentinaFil: Alvarez, Hector Manuel. Universidad Nacional de la Patagonia "San Juan Bosco". Instituto de Biociencias de la Patagonia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biociencias de la Patagonia; Argentina. Universidad Nacional de la Patagonia. Facultad de Ingeniería. Sede Puerto Madryn; ArgentinaLVII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research; XVI Annual Meeting of the Argentinean Society for General MicrobiologyMendozaArgentinaSociedad Argentina de Investigación BioquímicaSociedad Argentina de Microbiología Genera