Characterization of transesterification reactions by Mucoromycotina lipases in non-aqueous media

Publication date: Available online 19 February 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Alexandra Kotogán, Anita Kecskeméti, András Szekeres, Tamás Papp, Muthusamy Chandrasekaran, Shine Kadaikunnan, Naiyf S. Alharbi, Csaba Vágvölgyi, Miklós Takó Transesterification properties of Rhizomucor, Rhizopus, Mucor, Umbelopsis and Mortierella crude lipases were investigated in water-free systems using an UV spectrophotometric method. Conversion of p-nitrophenyl palmitate (pNPP) with ethanol was characterized under various reaction conditions. Best conversion yields were generally obtained at 40°C in n-heptane, but temperature of 50°C and the solvents hexane and isooctane proved to be also useful. Then, crude lipases from five strains, namely Rhizomucor miehei NRRL 5282, Rhizopus oryzae NRRL 1526, Rhizopus stolonifer SZMC 13609, Mucor corticolus SZMC 12031 and Mortierella echinosphaera CBS 575.75 were selected for further kinetic studies and to evaluate the effect of the acyl acceptors and donors with various chain lengths on the reaction. In general, ethanol up to 4.25mol/L concentration enhanced the catalytic activities, and a steady conversion with maximum yields ranging from 61.2% to 90.5% was obtained at about 96h. Replacement of ethanol as the acyl acceptor with methanol, isopropanol, n-butanol or n-hexanol resulted in lower conversions when incubated with the same concentration. The selected crude lipases demonstrated hig...

Source: Journal of Molecular Catalysis B: Enzymatic - February 21, 2016 Category: Biochemistry Source Type: research