02268nas a2200229   4500008004100000022001400041245010000055210006900155260005700224300001200281490000700293520143300300653003201733653001401765653003001779653002601809653001701835100001901852700001701871700002601888856012401914       2010                        eng d  a0046-899100aLipase of aspergillus niger NCIM 1207: a potential biocatalyst for synthesis of isoamyl acetate0 aLipase of aspergillus niger NCIM 1207 a potential biocatalyst fo  a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcOCT  a432-4370 v503 a<p>Commercial lipase preparations and mycelium bound lipase from Aspergillus niger NCIM 1207 were used for esterification of acetic acid with isoamyl alcohol to obtain isoamyl acetate. The esterification reaction was carried out at 30 degrees C in n-hexane with shaking at 120 rpm. Initial reaction rates, conversion efficiency and isoamyl acetate concentration obtained using Novozyme 435 were the highest. Mycelium bound lipase of A. niger NCIM 1207 produced maximal isoamyl acetate formation at an alcohol/acid ratio of 1.6. Acetic acid at higher concentrations than required for the critical alcohol/acid ratio lower than 1.3 and higher than 1.6 resulted in decreased yields of isoamyl acetate probably owing to lowering of micro-aqueous environmental pH around the enzyme leading to inhibition of enzyme activity. Mycelium bound A. niger lipase produced 80 g/l of isoamyl acetate within 96 h even though extremely less amount of enzyme activity was used for esterification. The presence of sodium sulphate during esterification reaction at higher substrate concentration resulted in increased conversion efficiency when we used mycelium bound enzyme preparations of A. niger NCIM 1207. This could be due to removal of excess water released during esterification reaction by sodium sulphate. High ester concentration (286.5 g/l) and conversion (73.5%) were obtained within 24 h using Novozyme 435 under these conditions.</p>10aAspergillus niger NCIM 120710aFusel oil10aIsoamyl acetate formation10aMycelium bound lipase10aNovozyme 4351 aMhetras, Nutan1 aPatil, Sonal1 aGokhale, Digambar, V.  uhttps://library.ncl.res.in/content/lipase-aspergillus-niger-ncim-1207-potential-biocatalyst-synthesis-isoamyl-acetate-0