minimal defined medium with 5 g/L glucose

Biomass concentrations were monitored by measuring optical density (OD) at 600nm with a spectrophotometer (model Novaspec II, Pharmacia Biotech, USA). The correlation of OD with biomass dry weight (0.486 gDW/l OD) had previously been determined from a batch culture grown on ... 10 g/l glucose minimal medium. To determine the extracellular concentrations of glucose, ethanol, acetate, pyruvate, succinate and glycerol, 1 ml samples were taken and centrifuged for 4 min at 4000 r.p.m. at 4ºC. The supernatant was analyzed with an HPLC system (Agilent HP1100) as described by [1], equipped with a polymer column (Aminex HPX-87H from BioRad, Switzerland). As eluent 5mM H2SO4 was used and the column was heated to 60ºC. The compounds were detected and quantified with a refractive index (RI) detector and an UV/Vis-detector (DAD). For absolute quantification, calibration curves with external standards for the corresponding pure substance obtained from Sigma (Switzerland) were used.

----------References------------
[1] Heer D, Sauer U (2008). Identification of furfural as a key toxin in lignocellulosic hydrolysates and evolution of a tolerant yeast strain. Microb Biotechnol 1: 497–506. http://doi.org/bmdjnc