Abstract An optimized very high gravity (VHG) glucose medium supplemented with low cost nutrient sources was used to evaluate bio-ethanol production by 11 Saccharomyces cerevisiae strains. The industrial strains PE-2 and CA1185 exhibited the best overall fermentation performance, producing an ethanol titre of 19.2% (v/v) corresponding to a batch productivity of 2.5 g l?1 h?1, while the best laboratory strain (CEN.PK 113-7D) produced 17.5% (v/v) ethanol with a productivity of 1.7 g l?1 h?1. The results presented here emphasize the biodiversity found within S. cerevisiae species and that naturally adapted strains, such as PE-2 and CA1185, are likely to play a key role in facilitating the transition from laboratory technological breakthroughs to industrial-scale bio-ethanol fermentations. phone: +351-253-604400 (Domingues, Lucilia) luciliad@deb.uminho.pt (Domingues, Lucilia) IBB?Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho - Campus de Gualtar - 4710-057 - Braga - PORTUGAL (Pereira, Francisco B.) IBB?Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho - Campus de Gualtar - 4710-057 - Braga - PORTUGAL (Guimar?es, Pedro M. R.) IBB?Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho - Campus de Gualtar - 4710-057 - Braga - PORTUGAL (Teixeira, Jose A.) IBB?Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho - Campus de Gualtar - 4710-057 - Braga - PORTUGAL (Domingues, Lucilia) PORTUGAL Registration: 2010-06-15 Received: 2010-04-26 Accepted: 2010-06-14 ePublished: 2010-06-24