Influence of individual HXT transporters in xylose fermentation by recombinant Saccharomyces cerevisiae strains
نویسندگان
چکیده
Background Lignocellulosic biomass is an attractive raw material for bioethanol production since it is an abundant and renewable feedstock that does not compete with food and feed production [1]. Xylose is the most abundant pentose present on these feedstocks, and although S. cerevisiae cannot readily ferment this sugar, the overexpression of the genes for xylose reductase (XR) and xylitol dehidrogenase (XDH) from P. stiptis and xylulokinase (XK) from S. cerevisiae allows the utilization of xylose [2]. However S. cerevisiae also lacks specific transporters for this sugar and thus the uptake of xylose is carried out by native hexose transporters encoded by the HXT1-HXT7 genes [3]. In the present report we analyzed the impact of individual HXT transporters on xylose fermentation by recombinant S. cerevisiae yeast strains overexpressing the genes for XR, XDH and XK [4].
منابع مشابه
Improving pentose fermentation by preventing ubiquitination of hexose transporters in Saccharomyces cerevisiae
BACKGROUND Engineering of the yeast Saccharomyces cerevisiae for improved utilization of pentose sugars is vital for cost-efficient cellulosic bioethanol production. Although endogenous hexose transporters (Hxt) can be engineered into specific pentose transporters, they remain subjected to glucose-regulated protein degradation. Therefore, in the absence of glucose or when the glucose is exhaust...
متن کاملA dynamic flux balance model and bottleneck identification of glucose, xylose, xylulose co-fermentation in Saccharomyces cerevisiae.
A combination of batch fermentations and genome scale flux balance analysis were used to identify and quantify the rate limiting reactions in the xylulose transport and utilization pathway. Xylulose phosphorylation by xylulokinase was identified as limiting in wild type Saccharomyces cerevisiae, but transport became limiting when xylulokinase was upregulated. Further experiments showed xylulose...
متن کاملCharacterization of the xylose-transporting properties of yeast hexose transporters and their influence on xylose utilization.
For an economically feasible production of ethanol from plant biomass by microbial cells, the fermentation of xylose is important. As xylose uptake might be a limiting step for xylose fermentation by recombinant xylose-utilizing Saccharomyces cerevisiae cells a study of xylose uptake was performed. After deletion of all of the 18 hexose-transporter genes, the ability of the cells to take up and...
متن کاملGrowth of a Saccharomyces cerevisiae strain lacking hexose transporters in different sugars after transformation with a Scheffersomyces stipitis genomic library
Background Brazil is the biggest ethanol producer in the world using sugarcane as substrate. From this process, bagasse is the main resulting by-product which can be used to produce second generation ethanol. Although Saccharomyces cerevisiae is the ideal yeast for the fermentative process, it cannot ferment xylose, one of the most abundant sugars in lignocellulosic biomass. Different yeast can...
متن کاملComparison of heterologous xylose transporters in recombinant Saccharomyces cerevisiae
BACKGROUND Baker's yeast (Saccharomyces cerevisiae) has been engineered for xylose utilization to enable production of fuel ethanol from lignocellulose raw material. One unresolved challenge is that S. cerevisiae lacks a dedicated transport system for pentose sugars, which means that xylose is transported by non-specific Hxt transporters with comparatively low transport rate and affinity for xy...
متن کامل