Improved bioprocess for enhanced xylitol synthesis by newly isolate Meyerozyma caribbica (CP02)

Abstract

Abstract The present work models the fermentation process parameters of the newly isolated, Meyerozyma caribbica CP02 for enhanced xylitol production and its fermentability study on rice straw hydrolysate. The impact of process variables was initially studied one at a time each followed by statistical validation. Temperature 32°C, pH 3.5, 200 rpm, 1.5% (v/v) inoculum, 80 gL− 1 initial xylose was optimized and a sequential two-stage agitation in fermentation process was adopted. At optimized conditions, xylitol yield of 0.77 gg− 1 and 0.64 gg− 1 was actualized using media containing commercial and rice straw derived xylose, respectively. For scale up, in 3L batch bioreactor, the highest xylitol yield (0.63 gg− 1) was attained at 72 h with media containing rice straw derived xylose (59.22 gL− 1) along with inhibitors (1.82 gL− 1 aliphatic acids, 0.141 gL− 1 furans, 0.95 gL− 1 total phenols). This implies, M. caribbica CP02 demonstrated good hydrolysate fermentability even at high initial xylose concentration. Therefore, isolate CP02 has potential commercial feasibility in bio-refineries for high yield xylitol production with minimal hydrolysate processing.