INVESTIGADORES
ALVAREZ Hector Manuel
congresos y reuniones científicas
Título:
Effective hydrocarbon biodegradation by an indigenous Rhodococcus sp. under natural environmental conditions of semiarid soil
Autor/es:
HARO PA; VILLALBA MS; SILVA RA,; ALVAREZ HM
Lugar:
Messina ITALIA
Reunión:
Simposio; 14th International Biodeterioration & Biodegradation Symposium IBBS-14; 2008
Institución organizadora:
IBBS International
Resumen:
Several conditions may limit hydrocarbon degradation by natural populations of microorganisms in east Patagonia (Argentina), including cold and fluctuating temperatures, low moisture and low nutrient contents in soil. Bioaugmentation treatment using indigenous microorganims may improve the biodegradation capacity of the soil system in this region. We isolated a desiccation-tolerant Rhodococcus strain from a hydrocarbon-contaminated soil sample. Soil microcosm experiments were run in parallel to evaluate its efficiency for crude oil degradation in semiarid soil. Total hydrocarbon content amounted up to 3.5-4 % (w/w) in microcosms. The inoculation of this strain was particularly effective for hydrocarbon biodegradation in oligotrophic soil and under low humidity conditions (below 10 %, w/w). Inoculation by bacterial cells in low humidity microcosms resulted in high degradation rates (40.97 %) after 38 days of incubation, whereas native bacterial population in nutrient-amended microcosm promoted least degradation of crude oil (19.53 %) at the same time period. On the other hand, bacterial inoculation in oligotrophic soil microcosm promoted greater degradation (19.2 %) than non-inoculated oligotrophic microcosm (4 %). Approximately, 48.9 % degradation of the TPH was achieved in the nutrient-amended microcosm inoculated with the bacterial strain. Bacterial cells seemed to establish well in semiarid soil after inoculation, since its proportion in the total cell counts was maintained along the experiment. We conclude that the indigenous isolate may be well adapted to the soil and climate of this region, so its use for bioaugmentation will be a good strategy for bioremediation of hydrocarbon-contaminated soil in semiarid Patagonia.