Sun‐Mi Lee

Butanol production by Clostridium beijerinckii NCIMB 8052 was investigated using both batch and continuous cultures containing suspended or immobilized cells. In the batch reactor, the initial addition of acetate and butyrate into the culture media was found not only to enhance solvent production but also to affect the ratio of acetone/butanol, which might result from the metabolic changes in solvent production. Furthermore, the addition of butyrate to the medium prevented strain degeneration du

The heterologous expression of a highly functional xylose isomerase pathway in Saccharomyces cerevisiae would have significant advantages for ethanol yield, since the pathway bypasses cofactor requirements found in the traditionally used oxidoreductase pathways. However, nearly all reported xylose isomerase-based pathways in S. cerevisiae suffer from poor ethanol productivity, low xylose consumption rates, and poor cell growth compared with an oxidoreductase pathway and, additionally, often requ

These results suggest that the xylose isomerase pathway should be the pathway of choice for efficient xylose fermentation in S. cerevisiae as it can outperform strains with the oxidoreductase pathway in terms of yield and ethanol production and xylose consumption rates. Consequently, the strain developed in this study could significantly improve the prospect of biofuels production from lignocellulosic biomass.

Abstract Lignocellulosic biomass has considerable potential for the production of fuels and chemicals as a promising alternative to conventional fossil fuels. However, the bioconversion of lignocellulosic biomass to desired products must be improved to reach economic viability. One of the main technical hurdles is the presence of inhibitors in biomass hydrolysates, which hampers the bioconversion efficiency by biorefinery microbial platforms such as Saccharomyces cerevisiae in terms of both prod

Abstract Lignocellulosic biomass shows high potential as a renewable feedstock for use in biodiesel production via microbial fermentation. Yarrowia lipolytica , an emerging oleaginous yeast, has been engineered to efficiently convert xylose, the second most abundant sugar in lignocellulosic biomass, into lipids for lignocellulosic biodiesel production. Yet, the lipid yield from xylose or lignocellulosic biomass remains far lower than that from glucose. Here we developed an efficient xylose‐utili

The membrane transporter ZitB responsible for Zn(II) efflux in Escherichia coli was studied by site-directed mutagenesis to elucidate the function of individual amino acid residues. Substitutions of several charged or polar residues, H53, H159, D163 and D186, located in predicted transmembrane domains resulted in loss of ZitB function. In contrast, neither the amino-terminal nor the carboxy-terminal regions, both histidine-rich, were required for function.

The petrochemical industry has grown to meet the need for massive production of energy and commodities along with an explosive population growth; however, serious side effects such as greenhouse gas emissions and global warming have negatively impacted the environment. Lignocellulosic biomass with myriad quantities on Earth is an attractive resource for the production of carbon-neutral fuels and chemicals through environmentally friendly processes of microbial fermentation. This review discusses