title: New alkaline lipase from Rhizomucor variabilis: Biochemical properties and stability in the presence of microbial EPS.
abstract: A new strain of Rhizomucor variabilis producing an active extracellular lipase was identified and characterized in the present studies. The culture conditions were optimized and the highest lipase production amounting to 136 U/mL was achieved after 4 days of cultivation. The optimum pH (5.5) and temperature (28 °C) were determined as the best conditions for R. variabilis lipase production. The isolated enzyme preparation exhibited maximum activity at 40 °C and pH 8.0. Lipase from R. variabilis was stable up to 50 °C during 2 H retaining 80% of its initial activity. The enzyme was highly stable in the pH range of 7.0-9.0. Moreover, the addition of naturally obtained exopolysaccharides (EPS) significantly enhanced lipase activity. The presence of EPS derived from Ganoderma applanatum and Rhizobium leguminosarum enhanced the lipase activity, which was 22% and 31%, respectively, higher than that in the control experiments. Simultaneously, the pH activity profiles remained unchanged. The Michaelis-Menten constant and the turnover number of the enzyme for p-nitrophenyl palmitate in the standard assay conditions were estimated at a level of 0.631 mM and 0.674 Sec(-1) . In conclusion, the results obtained in this work present a newly isolated lipase preparation stabilized with EPS or without modification as a very effective tool for industrial application.
authors: Department of Biochemistry, Maria Curie-Sklodowska University, Lublin, Poland.
authors: Renata
authors: R
authors: Bancerz
authors: Department of Biochemistry, Maria Curie-Sklodowska University, Lublin, Poland.
authors: Monika
authors: M
authors: Osińska-Jaroszuk
authors: Department of Biochemistry, Maria Curie-Sklodowska University, Lublin, Poland.
authors: Magdalena
authors: M
authors: Jaszek
authors: Department of Biochemistry, Maria Curie-Sklodowska University, Lublin, Poland.
authors: Grzegorz
authors: G
authors: Janusz
authors: Department of Biochemistry, Maria Curie-Sklodowska University, Lublin, Poland.
authors: Dawid
authors: D
authors: Stefaniuk
authors: Department of Biochemistry, Maria Curie-Sklodowska University, Lublin, Poland.
authors: Justyna
authors: J
authors: Sulej
authors: Department of Genetics and Microbiology, Marai Curie-Sklodowska University, Lublin, Poland.
authors: Monika
authors: M
authors: Janczarek
authors: Department of Biochemistry, Maria Curie-Sklodowska University, Lublin, Poland.
authors: Anna
authors: A
authors: Jarosz-Wilkołazka
authors: Department of Biochemistry, Maria Curie-Sklodowska University, Lublin, Poland.
authors: Jerzy
authors: J
authors: Rogalski
mesh_terms: D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008049:Lipase / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism; D020103:Rhizomucor / Q000737:chemistry / Q000201:enzymology*; D013696:Temperature
chemical_list: D011134:Polysaccharides; D008049:Lipase
keywords: Rhizomucor variabilis; enzyme stability; exopolysaccharides; lipase