Phenol degradation by an enterobacterium: aKlebsiellastrain carries a TOL-like plasmid and a gene encoding a novel phenol hydroxylase

Abstract

Although phenol catabolism is described for many different microorganisms, there is no example for such a pathway in an enterobacterial strain. Here we characterize a Klebsiella oxytoca strain that grows on phenol as the only source of carbon and energy. As the key enzyme of phenol degradation, phenol hydroxylase was purified to apparent homogeneity. Compared with other phenol hydroxylases, the Klebsiella enzyme differs with respect to several properties: (i) SDS-PAGE and gel-filtration analysis of the purified protein revealed that the enzyme is a monomer with a molecular mass of 156 kDa; (ii) steady-state kinetic measurements resulted in a K(m) value of 0.22 mM for phenol; and (iii) the enzyme is both dependent on NADPH/FAD and sensitive to EDTA. Further degradation of catechol, the reaction product of phenol hydroxylase, may occur via the effective meta-fission pathway often located on TOL or TOL-like plasmids. Such a plasmid was prepared from the Klebsiella strain and further characterized. The given data demonstrate that the isolated strain exhibits all characteristics of an efficient phenol-degrading microorganism.

Cellular fatty acid patterns inPseudomonas sp. CF600 during catechol and phenol degradation in media supplemented with glucose as an additional carbon source

“…Numerous aerobic bacteria that use aromatic hydrocarbons as a sole carbon and energy source have been isolated from many environments; the associated degradation pathways and their genetic regulation have been elucidated (Gibson and Subramanian, 1984;Gibson and Parales, 2000;Sung et al, 2000;Annadurai et al, 2002). Currently, bacteria from the genus Pseudomonas, Acinetobacter, Klebsiella and Bacillus have been the subjects of many studies in the field of phenols biodegradation (Annez Ahamad and Kunhi, 1996;Chang et al, 1997;Ali et al, 1998;Heesche-Wagner et al, 1999;Beendorf et al, 2001).…”

Isolation and molecular identification of polyaromatic hydrocarbons- utilizing bacteria from crude petroleum oil samples

“…The presence of plasmids affects the hydrocarbon metabolism dramatically. For instance, a strain belonging to K. oxytoca has the ability to degrade phenol throughout the expression of a plasmid-coding phenol hydroxylase gene (Heesche-Wagner et al, 1999). However, enrichment with BH minimal medium supplemented with 1% yeast extract as a nitrogen source enhanced the growth greatly.…”

Isolation of Enterobacteria able to degrade simple aromatic compounds from the wastewater from olive oil extraction

“…Despite the existence of some research on the efficiency of fungi in the degradation of aromatic compounds, investigations dealing with bacteria able to grow on such compounds, especially those abundant in Pseudomonas strains able to degrade phenolic acids (Perez et al 1990;Hinteregger et al 1992), enrichment to yield an aerobic consortium (Zouari & Ellouz 1996), the screening of Pseudomonas metabolizing eugenol (Rabenhorst 1996) and the role of a TOL-like plasmid and a gene encoding a novel phenol hydroxylase in Klebsiella strain (Heesche-Wagner et al 1999) no other studies have been made on this subject. Therefore, the microbial diversity of the isolates and aromatic compound biodegradation in the environment are not yet well understood (Ammar et al 1986;Watanabe et al 1998).…”