ABSTRACT
From soils contaminated with polychlorinated biphenils (PCBs) a strain of Alcaligenes sp. able to grow in a mineral medium with a commercial mixture of PCBs as carbon source was isolated. This strain consumed up to 200 ppm in seven days in laboratory conditions. After 24 h of incubation, some new congeners of PCBs could be recognized by mass spectrometry. Through the identification of these compounds it was possible to postulate examples of possible transformations by dechlorinations of penta- and tetra-chlorinated congeners into tri-chlorinated ones. The properties of the isolated strain are appropriate for bioremediation of contaminated areas and also for using in bioreactors in order to remove the xenobiotic chemical.
A partir de suelos contaminados con bifenilos policlorados (PCBs) se aisló una cepa de Alcaligenes sp. capaz de crecer en medio mineral con una mezcla comercial de PCBs como fuente de carbono. Esta cepa consumió hasta 200 ppm de PCBs en siete días de incubación en condiciones de laboratorio. En 24 horas de incubación se han podido detectar nuevos congéneres de PCBs mediante espectrometria de masa. La identificación de estos compuestos ha permitido postular transformaciones de congéneres penta- y tetra-clorados que originarían derivados triclorados. Las propiedades de la cepa aislada son apropiadas para biorremediación y para su uso en biorreactores para eliminar estos compuestos xenobióticos.
Subject(s)
Alcaligenes/metabolism , Polychlorinated Biphenyls/metabolism , Soil Microbiology , Soil Pollutants/metabolism , Biodegradation, Environmental , Bioreactors , Chlorine/metabolism , Molecular StructureABSTRACT
A rapid and simplified system for the differentiation of nonfermentative Gram-negative bacilli, encountered frequently in clinical specimens, is presented for use in the clinical laboratory. Nonfermentative bacteria can be grouped initially by the motility, oxidase and OF glucose reactions. This grouping simplifies the choice of additional tests for further identification. The additional tests included Gram stain, acid production from 10% lactose agar, nitrate reduction, arginine dihydrolase activity, fluorescein production, deoxyribonuclease activity, hydrolysis of aesculin, growth at 42 degrees C, gelatinase activity and susceptibility to antibiotics.