The effect of various parameters such as pH, agitation and aeration was studied for maximum production of pectin lyase (PL) and pectate lyase (PGL) by a novel yeast strain Debaryomyces nepalensis in bioreactor. The optimal levels of pH, aeration and agitation rate was found to be 7.0, 300 rpm and 1 vvm, respectively. Under these conditions, D. nepalensis produced 14,200 U/L of PL and 12,000 U/L of PGL corresponding to a productivity of 600 U/L h and 500 U/L h of PL and PGL, respectively. Fed-batch production was studied by feeding inducer (lemon peel), carbon source (galactose) individually and in combination at 12 h of growth for enhanced production of PL and PGL. Combined feeding of inducer and carbon source at 12 h was found to be the best strategy for enhanced production of PL and PGL. Under these conditions, production of PL and PGL increased to 23,300 U/L and 22,400 U/L, respectively which corresponded to a productivity of 728 U/L h of PL and 700 U/L h of PGL, respectively. The production was increased by 1.6- and 1.8-fold and productivity by 1.2- and 1.4-fold for PL and PGL, respectively when compared to batch culture. © 2007 Elsevier Ltd. All rights reserved.