Caracterização de enzimas bacterianas de degradação de hidrocarbonetos aromáticos policíclicos / Characterization of bacterial enzymes of aromatic polycyclic hydrocarbons degradation

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2008

RESUMO

The polycyclic aromatical hydrocarbons (HAPs) are mutagenic and carcinogenic composites to the human beings and the animals that are introduced in the environment in great amounts, to its activities related to the extraction, the transport, the refining, the transformation and the use of the oil and of its derivatives. The enzyme use for the biodegradation HAPs in effluent liquids is a promising technology, however some practical problems in the use of enzymes in its free form exist, between them the instability of its structure. Many methods have been developed to increase the enzymatic stability, being the technique of immobilization of greater success. This work had as objective to get and to determine the environmental conditions that intervene with the enzymes activity, free and immobilized, of HAPS degradation. Isolated of Mycobacterium fortuitum, of Gordonia polyisoprenivorans e of Naphthalene-utilizing bacterium had been grown in half mineral and 250 broth LB I contend mg L anthracene or -1phenanthrene e its cells breached for sonication. With the free and immobilized cellular extract in alginate of sodium one determined the excellent conditions of pH (4,0-9,0, in the drain plugs acetate, phosphate and tris-HCl), of temperature (5-80ºC) and time of reaction (10-90 min.) for enzymes catechol 1,2-dioxigenase (C1,2O), catechol 2,3-dioxigenase (C2,3O) and protocatechol 3,4-dioxigenase (P3,4O). It was also evaluated the effect of the Cu, Mg, Hg, Mn, Fe, Ke NH in the activity of these enzymes. For the attainment of enzymes, broth LB was more efficient. Present enzyme C1,2O in the cellular extract of M. fortuitum e of G. polyisoprenivorans 25ºC presented greater activity in pH 8,0 and kept this activity during 60min. Present enzyme C2,3O in the cellular extract of M. fortuitum e G. polyisoprenivorans presented greater activity in pH 7,0 the 30 and 35ºC and kept this activity during 90min. Enzyme P3,4O presented greater activity in pH 8,0 35ºC and kept this activity during 60min. The Fe e Mn had increased the activity of three enzymes. The activity of three enzymes was reduced in the presence of ions Cu, Mg, Hg, Ke NH, with exception of enzyme C1,2O that presented increase of activity in the presence of Hg. The immobilized cellular extract having enzymes C1,2O, C2,3O and P3,4O present greater stability to the variations of pH, temperature, reaction time, comparing to the free cellular extract.

ASSUNTO(S)

analise do solo biologia do solo

ACESSO AO ARTIGO

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