Navegando por Palavras-chave "Monooxygenases"

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    Análise molecular dos genes nid e cyp e avaliação da degradação de pireno por isolados de Mycobacterium sp
    (Universidade Federal de São Paulo, 2017-07-07) Silva, Natalia Maria da [UNIFESP]; Niero, Cristina Viana [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Polycyclic aromatic hydrocarbons (PAHs) are compounds found in the environment as a result of incomplete combustion of organic matter or the anthropogenic activity of exploration, refining and petroleum derivatives. They have complex structures with low solubility in water and remain for long periods in the environment being considered pollutants. Mycobacterium vanbaalenii-PYR1 was the first described microorganism with the ability to degrade pyrene, a polycyclic aromatic hydrocarbon. Sequencing of the genome of this strain revealed the presence of a region specialized in the degradation of HPA, called region A, containing genes encoding dioxygenase (nid). In addition, genes dispersed in the genome that encode monooxygenases (cyp150) with involvement in the degradation of these compounds have been described. Thus, this work investigated the presence of the nid and cyp genes in five Mycobacterium sp isolates by PCR and hybridizations with specific probes, besides the degradation of pyrene by phenotypic tests and by gas chromatography coupled to mass spectrometry (GC-MS). In the first stage of the work, the identification of the isolates was performed by the analysis of three essential genes by sequencing and the results obtained allowed to conclude that the isolates of this study are related to M. vanbaalenii and M. austroafricanum species. All isolates analyzed showed the ability to degrade pyrene by phenotypic tests. Gas chromatographic analyzes suggest that the MYC038, MYC040 and MYC211 isolates degrade 69.5%, 60.3% and 50.5% pyrene, respectively, over a period of 14 days. PCR results and hybridizations revealed the presence of only nidA and cyp150 genes in all isolates analyzed. The nidB, nidA3, nidB3 and ferredoxin phtAcAd genes were not identified in any of the isolates analyzed in this study suggesting their absence. Analyzes of the nidB2 gene did not allow to conclude its presence / absence. These data re-inforce the hypothesis of the present work that there is polymorphism in the A region of these isolates, and may also imply the existence of a new pathway for the degradation of aromatic hydrocarbons.