In this work, Saccharomyces cerevisiae strains PE-2 and CAT-1, commonly used in the Brazilian fuel ethanol industry, were engineered for xylose fermentation, where the first fermented xylose faster than the latter, but also produced considerable amounts of xylitol. An engineered PE-2 strain (MEC1121) efficiently consumed xylose in presence of inhibitors both in synthetic and corn-cob hydrolysat...

Several pre-treatments are used to release sugars from lignocellulosic materials that produce second-generation ethanol (2G). This study aimed evaluate the kinetic of glucose and xylose through enzymatic physical treatments sugarcane bagasse residual forest biomass, focusing on ratio between hexose pentose. Enzymatic hydrolysis after hydrothermal pre-treatment under different conditions, at 170...

Syntheses of several plant polysaccharides involving in vitro glycosyl transfer from nucleotide sugars have now been reported using the enzymes present in particulate preparations from plant tissues. Such syntheses include starch from UDP-D-glucose1 or ADP-D-glucose,2 pectin from UDP-D-galacturonic acid,3 callose from UDP-D-glucose,4 and cellulose from GDP-D-glucose5 or UDP-D-glucose.6 Indirect...

BACKGROUND The commercialization of second-generation bioethanol has not been realized due to several factors, including poor biomass utilization and high production cost. It is generally accepted that the most important parameters in reducing the production cost are the ethanol yield and the ethanol concentration in the fermentation broth. Agricultural residues contain large amounts of hemicel...

Lignocellulosic and algal biomass are promising substrates for lactic acid (LA) production. However, lack of xylose utilization and/or sequential mixed-sugars (carbon catabolite repression, CCR) from hydrolysates by most microorganisms limits achievable titers, yields, productivities economical industry-scale This study aimed to design lignocellulose-derived efficient LA production a thermophil...

Integrated permeate channel (IPC) flat sheet membranes were examined for use as a reverse membrane bioreactor (rMBR) for lignocellulosic ethanol production. The fermenting organism, Saccharomyces cerevisiae (T0936), a genetically-modified strain with the ability to ferment xylose, was used inside the rMBR. The rMBR was evaluated for simultaneous glucose and xylose utilization as well as in situ...

Yeast xylose metabolism is generally considered to be restricted to respirative conditions because the two-step oxidoreductase reactions from xylose to xylulose impose an anaerobic redox imbalance. We have recently developed, however, a Saccharomyces cerevisiae strain that is at present the only known yeast capable of anaerobic growth on xylose alone. Using transcriptome analysis of aerobic che...

An economically viable production of second-generation bioethanol by recombinant xylose-fermenting Saccharomyces cerevisiae requires higher xylose fermentation rates and improved glucose–xylose co-consumption. Moreover, S. recognises as a non-fermentable rather than fermentable carbon source, which might partly explain why is not fermented into ethanol efficiently glucose. This study proposes p...

The utilization of glucose by muscle is thought to be limited by the rate at which glucose enters the muscle cell and insulin is believed to stimulate glucose uptake by speeding its entry (Levine & Goldstein, 1955; Park, Bornstein & Post, 1955; Park & Johnson, 1955). We have shown that the uptake of glucose by isolated rat diaphragm incubated in a bicarbonate-buffered medium is increased by ano...

BACKGROUND The efficient microbial utilization of lignocellulosic hydrolysates has remained challenging because this material is composed of multiple sugars and also contains growth inhibitors such as acetic acid (acetate). Using an engineered consortium of strains derived from Escherichia coli C and a synthetic medium containing acetate, glucose, xylose and arabinose, we report on both the mic...