1. Assistant Professor, Dept. of Bioresource Engineering, McGill Univ., Macdonald Campus, 21 111 Lakeshore Rd., Ste. Anne de Bellevue QC, Canada H9X 3V9 (corresponding author).
2. Researcher, Dept. of Chemical Engineering, Univ. of Cambridge, Pembroke St., Cambridge CB2 3RA, U.K.