Isolation of Lipolytic Bacteria from Environmental Resources for Biodegradation Polysorbates in Industrial Wastewater

Today, entrance of wastewaters, especially detergent and cleaner agent’s production industries wastewaters, to surface and underground waters is one of environmental pollution concerns. These wastewaters are containing detergents and surfactants, such as polysorbates and, because of exposure of human and other organisms, their degradation is of great important. This research analyses degradation of a non-ionic detergent in polysorbate group called Tween 80 (polysorbate 80) and studies effect of pH and temperature on degradation rate of this detergent, using lipolytic bacteria (isolated from Tehran oil refinery wastewater and activated sludge). For primary isolating of lipolytic bacteria, the TSA medium containing Tween 80 and olive oil has been, separatively, used. Then specific culture Tween agar and Tributyrin agar have been used to study for lipase enzyme bacteria production. Also for confirmation degradation, instrumental methods, spectrophotometer and FTIR were used. The results shows that the isolated bacteria are able to depredate polysorbate 80 by lipase enzyme production. Bacillus cereus was known as the best degradator after the identification of the molecular basis of sequencing 16S rRNA. Bacillus cereus ATCC 14579 (T), Pseudomonas aeruginosa and other Bacillus sp was known. The results showed that pH and temperature affects on the degradation of tween, and the Pseudomonas aeruginosa at acidic range of pH, two gram positive bacillus at alkali range of pH and three bacteria at 37 ˚C have the best degradation.