Effect of temperature on microcystin-LR removal and lysis activity on <i>Microcystis aeruginosa</i> (cyanobacteria) by an indigenous bacterium belonging to the genus <i>Achromobacter</i>

Microcystis is a frequent cyanobacterium bloom-forming with cosmopolitan distribution which can produce a hepatotoxin group called microcystins (MCs). These MCs are resistant to the traditional processes employed in the water treatment plants and they are often detected after conventional treatments. Because of this, the bio-removal studies have obtained a great interest in the last decades. In this work, a bacterial strain namely LG1 with the ability to remove microcystin-LR (MC-LR) under laboratory conditions was isolated from Rio de la Plata River and it was identified as Achromobacter spp. This ubiquitous bacterium was able to remove 79.5% MC-LR in 7 days with average removal time of 3.33 ± 0.08, 3.06 ± 0.05, and 2.77 ± 0.05 days at 28, 32, and 36 ± 1 °C, being higher at high temperature (36 °C) with an activation energy = 16.79 ± 1.99 kJ mol⁻¹. LG1 grew better at higher temperature (from 28 to 36 ± 1 °C) increasing the specific growth rate (μ) and reducing 2-fold the lag phase duration (LPD) without significant differences (p > 0.05) between maximum population density (MPD). In addition, LG1 showed a lysis activity on two M. aeruginosa native strains in 7 days measured as chlorophyll a (Chl-a) concentration. The lysis activity increased around 2-fold when increasing the temperature from 28 to 36 ± 1 °C. This is the first report of an indigenous bacterium belonging to the genusAchromobacter spp. isolated from the Rio de la Plata River with the capacity to remove MC-LR and lysis activity on M. aeruginosa.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Criotecnología de Alimento

Control of a Dual Fed Open End Winding SPMSM with a Floating Capacitor

Surface Permanent Magnet Synchronous Motor (SPMSM) are not the first choice when a motor drive is required to operate over a wide speed range with an extended Constant Power Speed Range (CPSR). Nevertheless, SPMSMs offer high torque density, high efficiency simple manufacturing process and robustness which makes them an attractive alternative to Interior PMSMs. The Open End Winding (OEW) dual inverter topology, with one of the two Voltage Source Inverters (VSI) connected to a floating capacitor (FC), has shown to be capable of significantly increasing the operating speed range and CPSR of the SPMSM at the price of an increased controller complexity. In this paper, the analytical state space model of the OEW-FC SPMSM is derived, a state feedback controller is proposed and a possible tuning strategy is given to allow for high dynamics over the whole operating range and simplified controller design and tuning

An enantioselective entry to cis-perhydroisoquinolines

An enantioselective route to cis-perhydroisoquinolines, involving a cyclocondensation reaction of (R)-phenylglycinol with a racemic oxoester, a stereoselective conjugate addition to an unsaturated bicyclic lactam, and the closure of the carbocyclic ring by a ring-closing metathesis as the key steps is reported. This route allows the preparation of 3-cyano derivatives as well as cis-octahydroisoquinolines bearing a quaternary center at the C4-position

An enantioselective entry to cis-perhydroisoquinolines

An enantioselective route to cis-perhydroisoquinolines, involving a cyclocondensation reaction of (R)-phenylglycinol with a racemic oxoester, a stereoselective conjugate addition to an unsaturated bicyclic lactam, and the closure of the carbocyclic ring by a ring-closing metathesis as the key steps is reported. This route allows the preparation of 3-cyano derivatives as well as cis-octahydroisoquinolines bearing a quaternary center at the C4-position