Produção de lipases por Yarrowia lipolytica e potencial aplicação em tratamento de soro de queijo

Abstract

The microbial physiology is a promising area of biotechnology for the synthesis of compounds of high value. The micro-organisms have advantages because of their shorter generation facilities to physiological and genetic changes and the wide variety of metabolic processes. The aim of this study was to degrade oils and fats from lipases produced by Yarrovia lipolytica. Factorial designs were used to investigate the effects of variables in three stages: fermentation for lipase production, bioproduct formulation for stabilization the catalytic action of lipases and treatment of whey for degradation of fats and oils. In the presence of a vegetable oil residue at 3 % and ammonium chloride at 0,2 g.L-1, during 48 h at 28 oC, lipases were produced under submerged cultivation. The cell-free liquid metabolic was stability with sodium sorbate at 0.5 %, glycerol at 5 %, RENEX-95 at 10 %. This bioproduct presented 177 UI.mL-1 of the lipase activity during 30 days of storage at room temperature (27 - 30 °C); it showed optimum pH at 5.0 and 7.0, optimum temperature of 50 oC and thermal stability for 120 min with retention of 100 % of the enzyme activity at 50 oC and pH 5,0. The application of the bioproduct at 7 % during 12 h degraded 98 % of oils and fats present in cheese whey. The lipases produced by Y. lipolytica and formulated with stability agents have potential to be applied in the degradation of oils and fats.