Produção de Biossurfactantes por bactérias degradadoras de petróleo isoladas de isópteros da Floresta Amazônica no município de Coari

Abstract

The present dissertation relates isoptera of the Amazonian forest, oil and biosurfactants. The isoptera were the target of this investigation because they live in association with innumerous microorganisms such as bacteria, flagellated protozoa among others that give them the incredible ability to degrade ligno-cellulosic material present in their main diet: wood. Lignin and petroleum have a chemical structure composed of aromatic rings, ie the PAHs that give these compounds recalcitrance and resistance to biodegradation. Biodegradable petroleum microorganisms have some abilities that facilitate the biodegradation process, and one of the strategies used is the release into the extracellular environment of biosurfactants, which act to reduce the surface and interfacial tension of the molecules, thus causing the biodegradation of hydrophobic compounds. Termites were collected in the city of Coari, from soil habitat and tree followed for the cultivation of consortium producing biosurfactant in minimal medium and oil as the only source of carbon, later the microorganisms belonging to the selected consortium were grown individually, and the microorganism with the highest potential was identified by the sequencing of the 16 S ribosomal RNA gene revealing the bacterium Psychrobacillus psychrodurans. Tests performed as Emulsifying Activity and Cell Hydrophobicity revealed statistical differences in the experiments involving Hexane, xylene and petroleum solvents in seven days of culture. In the detection test of biosurfactant production (droplet collapse) the drop formed by the cell-free supernatant evidenced the production of biosurfactant of 0.1% compared to the SDS surfactant. The reduction of the surface tension by the Du Noyu ring method in Kruss tensiometer was demonstrated using the bacterial supernatant at distinct cultivation times 1, 7 and 12 days and indicated a reduction of the surface tension of 72 mN / m² to approximately 54, 6 mN / m² in seven days of cultivation.