Biochemical conversion of sugarcane straw hemicellulosic hydrolyzate supplemented with co-substrates for xylitol production

Abstract

Biotechnological production of xylitol is an attractive route to add value to a sugarcane biorefinery, through utilization of the hemicellulosic fraction of sugarcane straw, whose availability is increasing in Brazil. Herein, supplementation of the sugarcane straw hemicellulosic hydrolyzate (xylose 57gL(-1)) with maltose, sucrose, cellobiose or glycerol was proposed, and their effect as co-substrates on xylitol production by Candida guilliermondii FTI 20037 was studied. Sucrose (10gL(-1)) and glycerol (0.7gL(-1)) supplementation led to significant increase of 8.88% and 6.86% on xylose uptake rate (1.11gL(-1)h(-1) and 1.09gL(-1)), respectively, but only with sucrose, significant increments of 12.88% and 8.69% on final xylitol concentration (36.11gL(-1)) and volumetric productivity (0.75gL(-1)h(-1)), respectively, were achieved. Based on these results, utilization of complex sources of sucrose, derived from agro-industries, as nutritional supplementation for xylitol production can be proposed as a strategy for improving the yeast performance and reducing the cost of this bioprocess by replacing more expensive nutrients.

Production and purification of xylitol by Scheffersomyces amazonenses via sugarcane hemicellulosic hydrolysate

“…Moreover, the decrease in acid concentration promoted the neutralization of broth, pH was increased from 5.63 up to a value of 6.78. Acetic acid consumption by other yeasts such as C. guilliermondii and S. stipitis has been reported . As stated by Felipe et al .…”

“…reported: Y P/S = 0.75 g g −1 , Q P = 0.48 g L −1 h −1 and η = 81.7% during growth hemicellulosic hydrolysate from sugarcane bagasse. Hernandez‐Perez et al . obtained values of Q P = 0.77 g L −1 h −1 and η = 70.0% when this yeast was grown in hemicellulosic hydrolysate from sugarcane straw.…”

“…Acetic acid consumption by other yeasts such as C. guilliermondii and S. stipitis has been reported. 36,[40][41][42] As stated by Felipe et al 43 and Pereira et al, 44 for some yeasts, the acid toxicity is important above 3 g L −1 . This can be related to the ability of yeast to use acetic acid as an energy source, because these organic acids may be used in the tricarboxylic acid cycle and metabolized to CO 2 and H 2 O, with ATP formation.…”

“…The fermentative parameters reached with S. amazonensis are slightly smaller when compared to the results obtained with C. guilliermondii by Chaud et al 41 reported: Y P/S = 0.75 g g −1 , Q P = 0.48 g L −1 h −1 and η = 81.7% during growth hemicellulosic hydrolysate from sugarcane bagasse. Hernandez-Perez et al 40 obtained values of Q P = 0.77 g L −1 h −1 and η = 70.0% when this yeast was grown in hemicellulosic hydrolysate from sugarcane straw. However, the fermentation parameters obtained in this work were higher than those reported by Vallejos et al, 14 during the growth of Candida tropicalis in hemicellulosic liquors obtained from sugarcane bagasse autohydrolysis (Y P/S = 0.46 g g −1 and Q P = 0.27 g L −1 h −1 ).…”

Evaluation of some lignocellulosic byproducts of food industry for microbial xylitol production by Candida tropicalis

“…It was demonstrated that 10 g/100 mL solid/liquid ratio and 1.25 % sulfuric acid would be appropriate for initial preparation of the hydrolysate before detoxification and concentration. Various lignocellulosic residues have been reported to be used for xylitol production, some of which were corncob (Cheng et al 2009; Kamat et al 2013; Ramesh et al 2013) sugarcane straw (Hernández-Pérez et al 2016), cotton stalks (Akpinar et al 2011), grape marc (Salgado et al 2012), cashew apple bagasse (Albuquerque et al 2015a), wheat straw (Canilha et al 2005), wood sawdust (Rafiqul and Mimi Sakinah 2012), vine trimming wastes (Rivas et al 2007), and rice husks (Rambo et al 2013). Chestnut shells have been used in some studies for different purposes (Aires et al 2016).…”