Hemicellulosic hydrolysates

Index Entries Arabitol Debaryomyces hansenii hemicellulose hydrolysate combined severity xylitol. 

When screening a large number of Lactobacillus strains for lactate production using hemicellulose hydrolysate, strains L. pentosus CHCC2355 and L. brevis CHCC2097 were selected and evaluated further (Garde et al, 2002). Each strain produced lactate with 88% (for L. pentosus) and 61% of the theoretical yield (L. brevis), respectively, from wheat straw hydrolysate without visible inhibition. The operation of the phosphoketolase pathway in these... 

Garde, A., Jonsson, G., Schmidt, A. S., and Ahring, B. K. 2002. Lactic acid production from wheat straw hemicellulose hydrolysate by Lactobacillus pentosus and Lactobacillus brevis. Bioresour. Technol., 81,217-223. 

Keywords Xylitol Inhibitor Furfural Vanillin Syringaldehyde Toxicity-Hemicellulose hydrolysate... 

The xylitol production rate is highest at very high xylose concentrations (80 g/1) [8, 10]. However, concentrating the hemicellulose hydrolysates using vacuum evaporation to achieve high xylose concentrations also concentrates the non-volatile inhibitors [11]. At these inhibitor concentrations, volumetric productivity actually declines [12-14]. Many studies have demonstrated the inhibitory effect of these hydrolysis-derived compounds on growth and production of products, such as ethanol and xylitol [15-16]. Concentrated hydrolysate requires detoxification for optimum xylitol production. 

The results of toxicity experiments performed using C. guilliermondii in batch fermentations are generally similar to that observed in other studies using semi-synthetic or actual hemicellulose hydrolysates for xylitol or ethanol production. Dominguez et al. 

In fermentation experiments employing semi-synthetic sugarcane bagasse hemicellulose hydrolysate containing 60-92 g/1 xylose, vanillin inhibited the metabolism of the yeast... 

The proportions of the monosaccharides obtained in hemicellulose hydrolysates will vary depending on the choice of raw material and the hydrolysis... 

Temperatures around 30 C have been utilized for xylitol production yeasts cultivated in synthetic medium or in hemicellulosic hydrolysates produced from... 

Jin P, Li S, Lu SG, Zhu JG, Huang H. (2011b). Improved 1,3-propanediol production with hemicellulosic hydrolysates (corn straw) as cosubstrate impact of degradation products on Klebsiella pneumoniae growth and 1,3-propanediol fermentation. Bioresource Technol, 102, 1815-1821. 

As cellulose only represents 30-40% of the lignocellulosic biomass, the utilization of only glueose in the fermentation would undeniably have an effect on the overall biomass to ethanol conversion yield. Therefore, it is necessary to eonsider the utilization of the hemicellulose hydrolysate in the development of the advanced generation bioethanol production process. ... 

Production of Fuel Ethanol from Hemicellulosic Hydrolysates... 

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