The biodegradation of aromatic hydrocarbons by bacteria

Abstract

Aromatic compounds of both natural and man-made sources abound in the environment. The degradation of such chemicals is mainly accomplished by microorganisms. This review provides key background information but centres on recent developments in the bacterial degradation of selected man-made aromatic compounds. An aromatic compound can only be considered to be biodegraded if the ring undergoes cleavage, and this is taken as the major criteria for inclusion in this review (although the exact nature of the enzymic ring-cleavage has not been confirmed in all cases discussed). The biodegradation of benzene, certain arenes, biphenyl and selected fused aromatic hydrocarbons, by single bacterial isolates, are dealt with in detail.

Degradation of naphthalene by thermophilic bacteria via a pathway, through protocatechuic acid

“…Benzoic acid could form by decarboxylation of o-phthalic acid. Known metabolic pathway of o-phthalic acid through protocatechuic acid enters the central metabolism as succinic acid by orto-cleavage of protocatechuic acid [1,2]. This was confirmed by detection of 3, 4-PCDase enzymatic activity.…”

“…Pathways by which mesophilic bacteria degrade aromatic hydrocarbons under aerobic conditions as well as enzymes involved in the metabolism of these hydrocarbons are well-studied [1][2][3][4]. On the other hand, little is known on the growth of thermophilic microorganisms on aromatic hydrocarbons, such as benzoic acid, cresols and phenols [5][6][7].…”

Hydrogen and Carbon Isotope Fractionation during Aerobic Biodegradation of Benzene

“…The limited spreading of petroleum hydrocarbon compounds is usually attributed to the occurrence of biodegradation. Numerous laboratory studies have confirmed that BTEX compounds can be biodegraded under aerobic (3) and anaerobic conditions (4)(5)(6). However, it is often difficult to prove biodegradation at field sites since concentration changes can also be due to physical processes such as dispersion and sorption.…”

Metabolism of 5‐Chlorosubstituted Muconolactones

“…Mineralization of chlorocatechols is usually achieved by an ortho-cleavage route modified for the metabolism of chloroarornatics , whereas methylaromatics are usually mineralized via metacleavage routes (Smith, 1990). The ortho-cleavage pathway modified for the metabolism of chlorocatechols was postulated to be analogous to the 3-oxoadipate pathway, and the respective ring-cleavage and cycloisomerizing enzymes to differ only in substrate specificity.…”