Characterization of three nitrogen fixing and hydrocarbon degrading strains isolated from Patagonian soil

Abstract

Acuña, A., Pucci, G.N., Pucci, O.H. (2010). Characterization of three nitrogen fixing and hydrocarbon degrading strains isolated from Patagonian soil. Ecosistemas 19(2):125-136.

The aim of this study is to characterize three hydrocarbon-degrading bacteria in absence of nitrogen. Three microorganisms were isolated from Patagonian soil with low nitrogen concentration and contaminated with hydrocarbons. These were identified by 16S rDNA and fatty acids. The hydrocarbon degradation profiles were studied in the presence and the absence of nitrogen with aliphatic, cyclic, aromatic and polyaromatic hydrocarbons. The ability to perform biological nitrogen fixation was studied by acetylene reduction and detection of the nifD gene. Furthermore, a study was conducted to determine the strains adaptation to different pH between 5 to 9, temperature of 15ºC, 28ºC, 37ºC and 65 ° C, and increasing concentrations of NaCl between 0 and 3M. The three isolated strains belong to the genera Pseudomonas, Bacillus and Gordonia, all with the ability to fix nitrogen. The strains degraded almost all hydrocarbons tested in the presence and absence of nitrogen. All microorganisms showed a good adaptation to changes in pH, temperature and NaCl concentration, having a good adaptation to major stress factors in Patagonian soil.