Degradation of straight-chain aliphatic and high-molecular-weight polycyclic aromatic hydrocarbons by a strain of Mycobacterium austroafricanum

• Published in: Journal of applied microbiology 2003-01, Vol.94 (2), p.230-239
• Main Authors: Bogan, B.W, Lahner, L.M, Sullivan, W.R, Paterek, J.R
• Format: Article
• Language: English
• Subjects: Alkanes - metabolism; Benzopyrenes - metabolism; biodegradation; Biodegradation of pollutants; Biological and medical sciences; bioremediation; Biotechnology; Culture Media; Environment and pollution; Fluorenes - metabolism; Fluorine - metabolism; Fundamental and applied biological sciences. Psychology; Hydrophobic and Hydrophilic Interactions; Industrial applications and implications. Economical aspects; Molecular Weight; mycobacterium; Mycobacterium - growth & development; Mycobacterium - metabolism; Phenanthrenes - metabolism; polluted soils; polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - metabolism; Pyrenes - metabolism; soil bacteria; soil remediation
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1046/j.1365-2672.2003.01824.x

Aims: Our goal was to characterize a newly isolated strain of Mycobacterium austroafricanum, obtained from manufactured gas plant (MGP) site soil and designated GTI‐23, with respect to its ability to degrade polycyclic aromatic hydrocarbons (PAHs). Methods and Results: GTI‐23 is capable of growth on phenanthrene, fluoranthene, or pyrene as a sole source of carbon and energy; it also extensively mineralizes the latter two in liquid culture and is capable of extensive degradation of fluorene and benzo[a]pyrene, although this does not lead in either of these cases to mineralization. Supplementation of benzo[a]pyrene‐containing cultures with phenanthrene had no significant effect on benzo[a]pyrene degradation; however, this process was substantially inhibited by the addition of pyrene. Extensive and rapid mineralization of pyrene by GTI‐23 was also observed in pyrene‐amended soil. Conclusions: Strain GTI‐23 shows considerable ability to mineralize a range of polycyclic aromatic hydrocarbons, both in liquid and soil environments. In this regard, GTI‐23 differs markedly from the type strain of Myco. austroafricanum (ATCC 33464); the latter isolate displayed no (or very limited) mineralization of any tested PAH (phenanthrene, fluoranthene or pyrene). When grown in liquid culture, GTI‐23 was also found to be capable of growing on and mineralizing two aliphatic hydrocarbons (dodecane and hexadecane). Significance and Impact of the Study: These findings indicate that this isolate of Myco. austroafricanum may be useful for bioremediation of soils contaminated with complex mixtures of aromatic and aliphatic hydrocarbons.