Pretreated sugar refinery wastewater (SRWW) was used for the production of hydrogen by Rhodobacter sphaeroides O.U.001 in a 0.4 1 column photobioreactor. Hydrogen was produced at a rate of 0.001 1 hydrogen/h/l culture in 20% dilution of SRWW. To adjust the carbon concentration to 70 mM and nitrogen concentration to 2 mM, sucrose or l-malic acid was added as carbon source and sodium glutamate was added as nitrogen source to the 20% dilution of SRWW. By these adjustments, hydrogen production rate was increased to 0.005 1 hydrogen/h/l culture. Continuous hydrogen production was achieved in the same medium for 100 days at three different dilution rates. The maximum hydrogen produced was 2.67 1 tin 100 days) at a dilution rate of 0.0013 h(-1) (C) 2000 international Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.