New cultive medium for bioconversion of C5 fraction from sugarcane bagasse using rice bran extract

Abstract

The use of hemicellulosic hydrolysates in bioprocesses requires supplementation as to ensure the best fermentative performance of microorganisms. However, in light of conflicting data in the literature, it is necessary to establish an inexpensive and applicable medium for the development of bioprocesses. This paper evaluates the fermentative performance of Scheffersomyces (Pichia) stipitis and Candida guilliermondii growth in sugarcane bagasse hemicellulosic hydrolysate supplemented with different nitrogen sources including rice bran extract, an important by-product of agroindustry and source of vitamins and amino acids. Experiments were carried out with hydrolysate supplemented with rice bran extract and (NH4)2SO4; peptone and yeast extract; (NH4)2SO4, peptone and yeast extract and non-supplemented hydrolysate as a control. S. stipitis produced only ethanol, while C. guilliermondii produced xylitol as the main product and ethanol as by-product. Maximum ethanol production by S. stipitis was observed when sugarcane bagasse hemicellulosic hydrolysate was supplemented with (NH4)2SO4, peptone and yeast extract. Differently, the maximum xylitol formation by C. guilliermondii was obtained by employing hydrolysate supplemented with (NH4)2SO4 and rice bran extract. Together, these findings indicate that: a) for both yeasts (NH4)2SO4 was required as an inorganic nitrogen source to supplement sugarcane bagasse hydrolysate; b) for S. stipitis, sugarcane hemicellulosic hydrolysate must be supplemented with peptone and yeast extract as organic nitrogen source; and: c) for C. guilliermondii, it must be supplemented with rice bran extract. The present study designed a fermentation medium employing hemicellulosic hydrolysate and provides a basis for studies about value-added products as ethanol and xylitol from lignocellulosic materials.

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

“…(a)), while arabinose (data not shown) was not assimilated by the yeast. The assimilation of arabinose by other species of genus Scheffersomyces is not very common, and similar behavior was also observed in S. stipitis , which is commonly used for producing bioethanol from hemicellulosic hydrolysates …”

“…The formation and consumption of ethanol and glycerol during xylitol production by C. guilliermondii has been previously reported, as well as glycerol formation by S. stipitis during the fermentation of hemicellulosic hydrolysates from sugarcane bagasse to produce ethanol . Both glycerol and ethanol are expected as byproducts from xylose metabolism for some yeasts, whose production is linked to the glycolytic pathway.…”

“…The assimilation of arabinose by other species of genus Scheffersomyces is not very common, 34,35 and similar behavior was also observed in S. stipitis, which is commonly used for producing bioethanol from hemicellulosic hydrolysates. [36][37][38][39] Consumption of 96% of the acetic acid was also observed at 96 h (see Fig. 3(a)).…”

Evaluation of the Simultaneous Production of Xylitol and Ethanol from Sisal Fiber

“…In sequence, the solution was transferred to smaller containers, and yeast from the yeast-malt extract agar (YMA) culture was added to the medium. The Erlenmeyer flasks were kept under an agitation of 200 rpm and a temperature of 30 °C for 24 h [ 48 ].…”

Synthesis of polypropylene/cellulosic fiber composites using Ziegler‐Natta catalyst by in situ polymerization

“…Lignin is a complex amorphous polymer whose structure is not fully known. It provides rigidity and strength to all cellulose fibers . Lignin is always associated with hemicellulose in physical mixtures and chemical bonds .…”