Degradation of long-chain n-alkanes in soil microcosms by two actinobacteria

Abstract

The ability of two recently isolated actinobacteria, that degrade medium and long chain n-alkanes in laboratory water medium, was investigated in soil microcosms using different standard soils that were artificially contaminated with n-alkanes of different length (C₁₂- C₂₀- C₂₄- C₃₀). The two strains, identified as Nocardia sp. SoB and Gordonia sp. SoCp, revealed a similar high HC degradation efficiency with an average of 75% alkane degraded after 28 days incubation. A selectivity of bacteria towards n-alkanes of different length was detected as well as a consistent effect of soil texture and other soil physical chemical characteristics on degradation. It was demonstrated the specific aptitude of these selected strains towards specific environmental conditions.

Keywords:

• Bioremediation
• soil microcosms
• GC-MS
• n-alkanes
• Nocardia
• Gordonia

Acknowledgments

The authors acknowledge Professor Stefano Colazza and Giuseppe Alonzo (University of Palermo) for their kind scientific cooperation. This study was partly supported by the Italian Ministry of Education, University and Research (MIUR ex 60%, 2007).