Agave syrup as a substrate for inulinase production by Kluyveromyces marxianus NRRL Y-7571

Abstract

The factorial planning was used to plan and optimize inulinase production by the yeast Kluyveromyces marxianus NRRL Y-7571. The experiments were conducted using a Central Composite Design (CCD) 22, at different concentrations of agave syrup (3.6 to 6.4%) and yeast extract (2.2 to 3.0%). After 96 hours of fermentation, the best condition for the inulinase production was 5% agave syrup and 2.5% yeast extract, which yielded an average of 129.21 U mL-1 of inulinase. Partial characterization of the crude enzyme showed that the optimal pH and temperature were 4.0 and 60°C, respectively. The enzyme showed thermal stability at 55°C for 4 hours.