Due to their recalcitrant nature, organochlorides are already found in environment and the search for alternatives to eliminate these compounds such as biodegradation using native microorganisms is of great interest. A screening trial to select environmental bacteria able to degrade DDD, PCP and dieldrin was conducted. Among 14 isolates, the soil bacteria Pseudomonas aeruginosa L2-1 showed the highest tolerance to increasing concentrations of the organochlorides and was selected for further studies. Biodegradation was assessed in liquid medium, varying the concentrations of glucose and the presence of rhamnolipids (RL). The best medium for the occurrence of biodegradation of the compounds contained 0.5% glucose, giving approximately 50% yield after three days of incubation. Results showed that the biodegradation rates of the organochlorides by P. aeruginosa L2-1 were greater at low concentrations of glucose and in the presence of rhamnolipids.

In this article we describe a peer review exercise used in undergraduate chemistry course in which the students wrote and prepared critique of scientific texts produced by other students in the class. We investigated, based on the critical comments made by the peers, evidences of the appropriation of scientific discourse and a better understanding of its practice by the students. Additionally, we present our own conclusions on the use of such exercise applied to an organic chemistry course offered to undergraduate chemistry students at a Brazilian public university

En este artículo se describe un ejercicio de revisión de pares empleado en un curso de la licenciatura en química, en el cual los estudiantes escribieron y prepararon una crítica a los textos científicos producidos por otros estudiantes de la clase. Se investigaron, con base en los comentarios críticos realizados por los pares, las evidencias de la apropiación del discurso científico y una mejor comprensión de su práctica por los estudiantes. Adicionalmente, se presentan nuestras propias conclusiones sobre tal ejercicio aplicado en un curso de química orgánica ofrecido en una universidad pública brasileña.