Stability of Lipases Produced by Yarrowia lipolytica in the Presence of Cheese Whey

Abstract

Countries traditionally importers of bioproducts such as Brazil, India and China have been strong growth in research, production and market expansion of enzymes that moved around U$ 6x1012 in 2011. There are predicting an estimate of market growth of 6.3 % in 2013. Among the hydrolytic enzymes, lipases are ofindustrial interest and occupy a prominent position in global trade. These enzymes hav e been produced bymicroorganisms in the presence of industrial waste. The cheese whey is a by-product that retains approximately 55 % of the nutrients in milk that can be metabolized by Yarrowia lipolytica in bioproducts of commercial value. This study aimed to investigate the production and stability of metabolic liquid with lipolytic activity. Lipases were produced by Yarrowia lipolytica in the presence of cheese whey, olive oil and glycerol. A 24 factorial planning with four replications at the central point was proposed to investigate the best condition for producing these enzymes. Erlenmeyer’s flasks (250 mL) were filled with 100 mL of liquid medium in the presence of the inoculum to 10 % v/v (106 CFU/mL). The flasks were incubated at 28 °C with shaking at 150 rpm. The samples were collected, centrifuged and the supernatant used to determine pH and enzyme activity during 60 days of storage. The production reached maximum lipase 132IU/mL at 120 h of cultivation at pH 7.3 in the presence of whey at 10 %, glycerol 6 % and olive oil 0.2 %. The bioproduct with maximum activity showed enzymatic stability (156 IU/mL) for 60 days of storage in both refrigerated at 4 °C, as in a room temperature, at 28 °C. The presence of glycerol in the culture medium improved the stability of lipases for such chemical agent is a polyol which inhibits both the oxidation reaction and avoids protein deamidation.