Volume 8, Number 3, p.p. 73–77
Intensification of mineral oil degradation process in soil by the introduction of Rhodococcus sp. strains
L. Amiranashvili,1 N. Gagelidze,1 L. Tinikashvili,1 Kh. Varsimashvili,1 E. Kirtadze,1 T. Torok2 and G. Kvesitadze1
1 S. Durmishidze Institute of Biochemistry and Biotechnology, 10th km, David Agmasheneblis Kheivani, 0159 Tbilisi, Georgia
2 Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, MS 70A 3317, 94720 Berkeley, California
Some physiological characteristics and the capability to degrade mineral oil in soil under sterile (laboratory) and natural conditions have been studied for Rhodococcus sp. MO 227 and Rhodococcus sp. MO 235 strains recently isolated from the soils of southern Georgia. Introduction of these cultures into soil containing mineral oil at concentrations of 2% and 10% under sterile conditions led to the diminution of toxicant concentration by 40–60% and 20–30%, respectively, at the end of 5 weeks. At 3% contamination with hydrocarbons under natural conditions, the introduction of bacterial strains Rhodococcus sp. MO 227 or Rhodococcus sp. MO 235 decreased the contamination in black soil by 60 and 50% and in red soil by 40 and 55%, respectively, after 15 weeks. This exceeds by 10–20% the level of degradation induced by indigenous microflora.
Keywords: degradation intensity, fertilizer, residual mineral oil, Rhodococcus, soil
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