One-step solid-state fermentation for efficient erythritol production from the simultaneous saccharified crop wastes by incorporating immobilized cellulase

Abstract

Crop wastes are advantaged feedstocks for low-cost erythritol production via Yarrowia procedure, whereas a high amount of cellulose remains in the fermentative medium due to the lack of cellulase. The present study proposed a one-step solid-state fermentation (SSF) for erythritol production from oil crop waste that was simultaneous saccharified by the incorporated exogenous cellulase. Cellulase was immobilized in alginate-chitosan beads, and the outstanding performance of the immobilized cellulase in erythritol cultivation was proven based on its tolerance to pH and osmotic pressure, with high stability and reusability (83% of activity maintained after five cycles of utilization). Under the optimal condition of pH 6.0 and 0.01 g/g dry substrate with the immobilized cellulase addition of 1.5% (w/w), persistent cellulase activity accompanied by the efficient consumption of total sugar was detected during the cultivation. Enhanced erythritol production was achieved with the highest titer of 226.8 mg/g dry substrate in scale-up batch fermentation, when the fed-batch cultivation contributed to a considerable total amount of erythritol. Cost analysis suggests that the present process leads toward the development of eco-friendly and economically feasible erythritol production.