Use of Yarrowia lipolytica Lipase Immobilized in Cell Debris for the Production of Lipolyzed Milk Fat (LMF)

Abstract

Lipase immobilized on Yarrowia lipolytica cell debris after sonication of yeast cells (LipImDebri) was used in hydrolysis reaction as a novel strategy to produce lipolyzed milk fat (LMF). Extracellular (4732.1 U/L), intracellular (130.0 U/g), and cell debris (181.0 U/g) lipases were obtained in a 4 L bioreactor using residual frying oil as inducer in 24 h fermentation process. LipImDebri showed a good operational stability retaining 70% of lipolytic activity after the second cycle and 40% after the fourth. The highest degree of hydrolysis (28%) was obtained with 500 mg LipImDebri for 6 h of lipolysis of anhydrous milk fat. LMF produced with LipImDebri presented high contents of oleic (35.2%), palmitic (25.0%), and stearic (15.4%) acids and considerable amounts of odor-active short and medium chain fatty acids (C:4–C:10) (8.13%).

Yarrowia lipolytica Adhesion and Immobilization onto Residual Plastics

“…After centrifugation (4 • C, 4600× g, for 5 min), the sonicated biomass (cell debris with lipase) was resuspended in 200 mM MOPS buffer pH 7.0 and frozen for subsequent measurement of enzyme activity. This sonicated biomass with high lipase activity [16,17] was used as a catalyst. It was resuspended in MOPS buffer, let adhere to solid surfaces (polystyrene and PET), as described in Section 2.4.2, and used as an immobilized biocatalyst.…”

“…Although it has been reported that Y. lipolytica cells present lipase enzymatic activity [15], a higher lipase activity is detected when the cells are treated with ultrasound, which results in cell debris associated with lipase [17]. Y. lipolytica cell debris were tested for lipase activity (hydrolysis of p-nitrophenyl laurate into p-nitrophenol), and a positive result was obtained, as depicted in Table 5 (before adhesion).…”

“…The adhesion of Y. lipolytica to Teflon-like thin films deposited on plasma-treated polycarbonate substrates resulted in a strong adhesion of cells, indicating its use for fixed bed biofilm reactors [7]. This yeast has also been studied broadly for lipase production [15][16][17]. In addition to the extracellular lipase fractions, Y. lipolytica can produce fractions that remain bound to the cell wall [15], as well intracellular fractions [16].…”

“…In addition to the extracellular lipase fractions, Y. lipolytica can produce fractions that remain bound to the cell wall [15], as well intracellular fractions [16]. Fraga et al [17] revealed that Y. lipolytica cells treated with ultrasound (cell debris) can be used as a catalyst in the hydrolysis of fat.In recent work, cells of Rhizopus oryzae with a 1,3-positional specificity lipase were immobilized on biomass support particles (polyurethane foam particles) and investigated for the methanolysis of soybean oil. This process is considered to be promising for biodiesel fuel production [6].…”

“…In addition to the extracellular lipase fractions, Y. lipolytica can produce fractions that remain bound to the cell wall [15], as well intracellular fractions [16]. Fraga et al [17] revealed that Y. lipolytica cells treated with ultrasound (cell debris) can be used as a catalyst in the hydrolysis of fat.…”