Bioprospecção de microrganismos lipolíticos obtidos de efluentes industriais

Abstract

Effluents rich in oils and fats are responsible for serious problems in sewage treatment systems, and major environmental impacts. An alternative for the treatment of such effluent is to use biological processes, including microorganisms that produce lipase enzymes. These enzymes are widely distributed in nature and have the capacity to degrade oils and fats contained in effluents, through hydrolysis of ester bonds of triacylglycerols. Lipases can catalyze other various reactions and are applicable in various industrial sectors. This study aimed to isolate and characterize microorganisms wich producers of lipases from different effluent food industries of Pelotas, Brazil. The bacteria were identified as the Gram’s stain and biochemical tests (Vitek 2® system), and the fungi were viewed as the macromorphology and micromorphology. The production of extracellular lipase was evaluated by testing rhodamine B, and enzyme activity by titration. Twenti-one bacterias were isolated, they are identified as Klebsiella pneumoniae ssp. pneumoniae, Serratia marcescens, Enterobacter aerogenes, Raoultella ornithinolytica and Raoultella planticola. Filamentous fungi isolated were characterized to the genera Alternaria sp., Fusarium sp., Geotrichum sp., Gliocladium sp., Mucor sp., Paecilomyces sp. and Trichoderma sp.. The production of extracellular lipase was observed in 71.43 % of the bacteria and 57.14% of fungi. As the enzymatic activity microrganimos that were more promising were E. aerogenes (1.53 U / ml), S. marcescens (0.87 U / ml) and K. pneumoniae ssp. pneumoniae (0.45 U / ml and 0.42 U / ml). The study reveals that there are microorganisms producing lipase present in industrial effluents, which can be effective in effluent treatment systems.