In this issue: Biotechnology Journal 5/2010

Baker's yeast for biofuel Yanase et al., Biotechnol. J. 2010, 5, 449–455 Environmental concerns and the depletion of oil reserves result in governmental incentives to establish greater energy independence. At present, research on environmentally friendly and sustainable biofuels focusses on ethanol. The yeast S. cerevisiae is a highly suitable microorganism for bioethanol production because of its high ethanol productivity, high ethanol tolerance, high endurance in industrial processes, and the simplicity of genetic engineering. However, S. cerevisiae cannot utilize cellulosic materials, and a cellulose saccharification process to produce glucose is necessary before fermentation. Scientists from Kobe (Japan) now demonstrate direct ethanol fermentation from amorphous cellulose using cellulase‐co‐expressing yeast. Cellulose degradation is increased 3‐ to 5‐fold and the ethanol yield was 2.1 g/L, showing that cell surface display of cellulase is highly suitable for direct ethanol fermentation from cellulose. PEGylation and chromatography Abe et al., Biotechnol. J. 2010, 5, 477–483 Although various technologies have been extensively studied as drug delivery systems, PEGylation, the covalent attachment of polyethylene glycol (PEG) chains to protein, is quite attractive for development of protein or peptide drugs. The retention and binding mechanisms in electrostatic interaction‐based chromatography (ion‐exchange chromatography) of PEGylated proteins is here investigated by researchers from Ube, Japan. Their findings indicate that when a protein is mono‐PEGylated, the binding site is not affected and the elution volume reduces due to the steric hindrance between PEGylated protein and ion‐exchange ligand. Automatable bilayer chips Poulos et al., Biotechnol. J. 2010, 5, 511–514 As a step towards an automated and operator‐free ion channel measurement platform, scientists from Incheon, Korea, have previously demonstrated a solution formulation for artificial lipid bilayers that enable indefinite storage and shipping of frozen bilayer precursors. Here, they have adapted pin tools to deposit the bilayer precursor solutions onto multi‐element arrays, which is a popular method for microarray solution deposition. The pin tools enable the deposited volume to be applied in a repeatable and highly controlled manner. This results in reduction of bilayer formation times to <1 h. The pin tools are also compatible with computerized motion control platforms, enabling automated and high throughput production. This technology can be applied to produce high density bilayer arrays for high throughput measurement of ion channels incorporated into artificial bilayers.