Abstract:
One of the most worrying environmental problems of the Ecuadorian Amazon is the oil spills, product of the oil exploitation [1]. To counteract the damage caused by this activity, PETROAMAZONAS-EP, through its "Live Amazon" Project (PAV), has dedicated itself to the bioremediation of soils contaminated by hydrocarbons [2]. The clay texture of the Amazonian soil is one of the factors that hinders bioremediation activities, due to its tendency to compaction and plasticization, high water retention capacity, poor aeration and low permeability [3,4,5]. All these characteristics together hinder the development of both microorganisms and plants [6]. In this context, the use of Rhizobium, a Gram-negative bacterium of free and native life of a contaminated soil, producing metabolites with a history of soil aggregation improvement such as exopolysaccharides (EPS) was proposed. This will allow the improvement of bioremediation processes, through changes in the soil structure that promote hydrocarbon degradation activity, which would result in cost reduction and saving of material and human resources in the process. To carry out this investigation, simple random sampling was carried out in different Liability Management Centers operated by the PAV. The samples collected corresponded to plant roots with typical characteristics of nodular legumes. From the nodules, a macerate was obtained and a Gram stain was performed to corroborate the presence of Gram negative bacilli. Subsequently, these were seeded in yeast-mannitol extract agar (YEMA) and the colonies that presented the common macroscopic characteristics of Rhizobium in the culture medium were selected for purification and again subjected to Gram staining to confirm the presence of gram negative bacilli.