The potential of oil-utilizing bacterial consortia associated with legume root nodules for cleaning oily soils

• Published in: Chemosphere (Oxford) 2009-03, Vol.74 (10), p.1354-1359
• Main Authors: Dashti, N., Khanafer, M., El-Nemr, I., Sorkhoh, N., Ali, N., Radwan, S.
• Format: Article
• Language: English
• Subjects: Applied sciences; Bacteria; Bacteria - genetics; Bacteria - metabolism; Bacteria - ultrastructure; Biodegradation of pollutants; Biodegradation, Environmental; Biological and medical sciences; Bioremediation; Biotechnology; Decontamination. Miscellaneous; DNA Primers - genetics; Earth sciences; Earth, ocean, space; Endophytes; Engineering and environment geology. Geothermics; Environment and pollution; Environmental Pollution - prevention & control; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Lupinus; Lupinus albus; Microscopy, Electron, Transmission; Oil-pollution; Periphytes; petroleum; Petroleum - metabolism; polluted soils; Pollution; Pollution, environment geology; Polymerase Chain Reaction; Rhizosphere; RNA, Ribosomal, 16S - genetics; root nodules; Root Nodules, Plant - metabolism; Root Nodules, Plant - microbiology; sand; sandy soils; Soil - analysis; Soil and sediments pollution; soil bacteria; Soil Pollutants - metabolism; soil pollution; Solanum melongena; Vicia faba
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2008.11.028

The surfaces of root nodules of Vicia faba and Lupinus albus (legume crops), were colonized with bacterial consortia which utilized oil and fixed nitrogen. Such combined activities apparently make those periphytic consortia efficient contributors to bioremediation of oily nitrogen-poor desert soils. This was confirmed experimentally in this study. Thus, cultivating V. faba, L. albus and, for comparison, Solanum melongena, a nonlegume crop, separately in oily sand samples resulted in more oil attenuation than in an uncultivated sample. This effect was more pronounced with the legume crops than with the nonlegume crop. Furthermore, in flask cultures, V. faba plants with nodulated roots exhibited a higher potential for oil attenuation in the surrounding water than plants with nodule-free roots. Denaturation gradient gel electrophoresis (DGGE) of polymerase chain reaction amplified 16S rRNA coding genes revealed that periphytic bacteria had DGGE bands not matching those of the oil-utilizing rhizospheric bacteria. Legume nodules also contained endophytic bacteria whose 16S rDNA bands did not match those of Rhizobium nor those of all other individual periphytic and rhizospheric strains. It was concluded that legume crops host on their roots bacterial consortia with a satisfactory potential for oil phytoremediation.