Anaerobic digestion of palm oil, ethanol, and tequila production by products: Effects of alkaline hydrothermal pre-treatment on sugars release and biogas composition

This study explored the interactions between alkaline hydrothermal pretreatment (AHPT) operational conditions temperature (°C), NaOH concentration (M) and residence time (min) on the compositional characteristics of the solid (SH) and liquid hydrolysate (LH) obtained from AHPT of sugarcane bagasse (SCB), empty fruit bunch (EFB) and agave bagasse...

Novel genetic parts and cultivation strategies for yeast-based conversion of lignocellulosic feedstocks

The recent start-up of several full-scale ‘second generation’ ethanol plants marks a major milestone in the development of Saccharomyces cerevisiae yeast strains for fermentation of lignocellulosic hydrolysates of agricultural residues and energy crops. In contrast to the fermentation of hexose sugar-rich substrates, such as corn syrup or sugar...

Laboratory evolution for forced glucose-xylose co-consumption enables identification of mutations that improve mixed-sugar fermentation by xylose-fermenting Saccharomyces cerevisiae

Simultaneous fermentation of glucose and xylose can contribute to improved productivity and robustness of yeast-based processes for bioethanol production from lignocellulosic hydrolysates. This study explores a novel laboratory evolution strategy for identifying mutations that contribute to simultaneous utilisation of these sugars in batch...

Fermentation of glucose-xylose-arabinose mixtures by a synthetic consortium of single-sugar-fermenting Saccharomyces cerevisiae strains

D-Glucose, D-xylose and L-arabinose are major sugars in lignocellulosic hydrolysates. This study explores fermentation of glucose-xylose-arabinose mixtures by a consortium of three ‘specialist’ Saccharomyces cerevisiae strains. A D-glucose- and L-arabinose-tolerant xylose specialist was constructed by eliminating hexose phosphorylation in an...

Laboratory evolution of a glucose-phosphorylation-deficient, arabinose-fermenting S. cerevisiae strain reveals mutations in GAL2 that enable glucose-insensitive l-arabinose uptake

Cas9-assisted genome editing was used to construct an engineered glucose-phosphorylation-negative S. cerevisiae strain, expressing the Lactobacillus plantaruml-arabinose pathway and the Penicillium chrysogenum transporter PcAraT. This strain, which showed a growth rate of 0.26 h−1 on l-arabinose in aerobic batch cultures, was subsequently...

Saccharomyces cerevisiae strains tor second-generation ethanol production: from academie exploration to industrial implementation

The recent start-up of several full-scale ‘second generation’ ethanol plants marks a major milestone in the development of Saccharomyces cerevisiae strains for fermentation of lignocellulosic hydrolysates of agricultural residues and energy crops. After a discussion of the challenges that these novel industrial contexts impose on yeast strains,...

The effects of combined catalysis of oxalic acid and seawater on the kinetics of xylose and arabinose dehydration to furfural

It is known that both acids and salts have a positive catalytic effect on the dehydration of pentoses to form furfural, a potentially attractive platform chemical. In this study the effects of the combined usage of an organic acid, instead of stronger mineral acids, and a saline catalyst is investigated. In order to assess these effects, the...

Cytosolic NADPH balancing in Penicillium chrysogenum cultivated on mixtures of glucose and ethanol

The in vivo flux through the oxidative branch of the pentose phosphate pathway (oxPPP) in Penicillium chrysogenum was determined during growth in glucose/ethanol carbon-limited chemostat cultures, at the same growth rate. Non-stationary 13C flux analysis was used to measure the oxPPP flux. A nearly constant oxPPP flux was found for all glucose...

Engineering of Saccharomyces cerevisiae for the production of fuel ethanol from xylose

For various reasons mankind is looking for alternatives for fossil fuels. One of these alternatives is ethanol made from plant biomass. However, the plant material when broken down by hydrolysis into its sugar monomers contains a significant amount of xylose, a 5-carbon-sugar or pentose. Contrary to the sugars with 6 carbon atoms (hexoses) wild...