Produção e formulação de biossurfactante de Pseudomonas cepacia UCP 6659 para aplicação na remoção de poluentes ambientais gerados na indústria de petróleo

Abstract

The search for natural, biodegradable and less toxic compounds has stimulated the development of alternative products. Biosurfactants, microbiologically obtained molecules, have become an important strategy in obtaining compounds more compatible with the environment. In this sense, we evaluated the production, characterization and application of a biosurfactant obtained from Pseudomonas cepacia UCP 6659 in the removal of petroleum derivative in soils and waters. Initially, the cultivation conditions were statistically optimized through a central rotational compound design (CCRD) regarding the influence of the variables culture time, inoculum concentration and rotation speed. The selected biosurfactant was characterized for the stability of the tensoactive and toxicological properties. Its production was investigated in a semi-industrial bioreactor of 50 L. The biosurfactant was formulated using three conservation methods and stored for 120 days. Subsequently, the biosurfactant was tested in the decontamination of petroleum derivatives and in bioremediation process. As results, the most significant levels selected by the DCCR were 250 rpm, 60h and inoculum of 1.5 %, reaching a surface tension of 27 mN/m, a yield of 8.0 g / L and a CMC of 600 mg / L. The chemical characterization (FTIR, 1H NMR and GC-MS) revealed its glycolipid and anionic nature. The biotensoativo presented efficient emulsifying activity in motor oil above 90 % and stability against extreme conditions (120°C, 12 % NaCl and pH of 2 to 12). The biosurfactant was non-toxic to microcrack Artemia salina and cabbage seeds (Brassica oleracea). With the increase of the scale of production, a concentration of 40.5 g / L in biosurfactant was reached, with a surface tension of 29 mN/m. The biosurfactant showed stability in all conservation methods, showing that it is economically feasible for large scale application, due to the low cost of obtaining the formulated product, estimated at around US$ 0.14-0.15 / L, and can be produced At a reduced cost compared to those commercially available on the world market. The biosurfactant demonstrated efficacy of up to 75 % recovery of residual oil from samples of oil-saturated sand, 81 % dispersion of petroderivative in sea water and recovery of 90 % of motor oil on solid surface. The formulated product reached 76.55 % oil removal, 84.5 % in sea stones, and promoted 70 % oil biodegradation in sea water. Therefore, the biosurfactant produced by P. cepacia presents potential for application in the petroleum industry and in the decontamination of petroderivatives in the environment.