Most pharmaceutical compounds have asymmetric nature and are optically active. Compounds with one asymmetric centre (chiral centre) would exhibit two enantiomeric forms and among them one is pharmacologically active (eutomer) while the other one contributed side effects or toxic effects or totally inert (distomer) [1] . Hence, current interest is towards development and administration of eutomer instead of its racemic mixture to improve therapeutic efficacy and reduce the unwanted effects due to the distomer [2] . Biocatalysts have excellent selectivity under mild reaction conditions [2] and hence in this study various whole-cell microorganisms like Bacillus subtilis [3] , Escherichia coli [4] , Pseudomonas putida [5] , Sphingomonas paucimobilis [6] , Rhodococcus erythropolis [7] , Streptomyces halstedii [8] , Aspergillus niger [9] , Candida parapsilosis [10] , Geotrichum candida [11] , Rhizopus oryzae [12] , Cunninghamella elegans [13] and Cunninghamella blakesleeana [14] were employed as biocatalysts for the stereo inversion of racemic sotalol to its active enantiomer. However, a limitation for using whole-cell microorganisms as biocatalysts is reduced stereo selectivity due to competition between multiple enzymes of the microorganism for the same substrate [15] . The use of isolated pure enzymes with suitable cofactors as biocatalysts would help overcome this limitation of using whole-cell microorganisms [16] and the reactions catalysed by pure enzymes also serves some other advantages like they are highly selective under mild conditions, more catalytic in nature and environmentally benign [2] . Lipases have great versatility in catalysing different reactions like aminolysis, esterification, transesterification and interesterification. The means followed by lipases to catalyse these reactions can be described as a ping-pong bi-bi mechanism. Accordingly, first step involves nucleophilic attack on the carbonyl group of a drug, which results in acyl-