PROIMI   05436
PLANTA PILOTO DE PROCESOS INDUSTRIALES MICROBIOLOGICOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Actinobacteria and maize plants: a promising biological system to remove lindane from soils
Autor/es:
ALVAREZ A; POLTI MA; BENIMELI C.S.; CUOZZO S.A; FUENTES M.S.; SAEZ MJ; COLIN V.L.; DAVILA COSTA JS; AMOROSO M.J.
Lugar:
La Falda, Córdoba
Reunión:
Workshop; PGPR LATINOAMERICA 2014; 2014
Institución organizadora:
Universidad Nacional de Río Cuarto
Resumen:
Introduction. Highly toxic organochlorine pesticides (OPs) like lindane have been released into the environment. Although nowadays its use is banned, it continues causing serious environmental and health concerns. Actinobacteria have a great potential for the bioremediation of toxic compounds, while several plants not only promote growth of microbial degraders, but also have pesticide degrading-activities. Objective. To evaluate lindane dissipation by an actinobacteria consortium cultivated with maize plants. Materials and Methods. Four Streptomyces strains previously isolated from soils contaminated with OPs were cultured on pots filled with sterile soil spiked with lindane (2 mg Kg-1). Strains were inoculated in the pots as mixed culture and one maize plant was planted per pot. Treatments (repeated 3 times) were as follows: lindane-plant-consortium; plant-consortium; lindane-consortium and lindane-plant. Appropriates controls were made. Pots were incubated at 30 ºC, and soil samples were taken at 0,7,14 and 21 days for determining microbial growth (CFU g-1), residual lindane (by Gas Chromatography) and for ecotoxicity testing using lettuce seedlings. The vigor index (VI) of lettuce were calculated (VI=average seedlings length x percentage of germination/10). Results. The consortium was able to growth on the three conditions assayed, although differences among CFU g-1 per treatment and per time were registered. At the 7th day, the consortium grew more on the lindane-plant-consortium condition (1.0x106±1.5x105) than in the lindane-consortium condition (2.9x105±2.0x104) (P0.05). On the other hand, at 14 days, microbial growth was quite similar among the treatments (P>0.05). At 21 days, microbial growth reached almost the same value in lindane-plant-consortium (2.0x107±1.8x106) than in lindane-consortium condition (1.9x107±1.2x105). Microbial growth in the consortium-plant condition was slightly lower (1.0x107±4.5x105) than the growth registered on polluted soils (P>0.05). Significant microbial growth was not recorded in the controls. Pesticide dissipation was evidenced in all treatments, although this process was variable among them, along the time. From the 7th day, significant lindane dissipation was registered in lindane-plant-consortium as well as in the lindane-plant condition, reaching at the 14th day, 17.6±2.9% (lindane-plant-consortium) and 39.6±1.3% (lindane-plant) of lindane removal (P0.05). On the other hand, the bioremediation process in the lindane-consortium treatment (without plant) was evidenced from the beginning of the experiment, reaching 13.7±1.2% of pesticide removal at the 7th day, 34.5±5.7% at 14 days and 37.8±5.6% at 21 days. Lindane removal obtained in this treatment at the end of the experiment, was different at statistical level (P