초록
Photofermentative H<SUB>2</SUB> production at higher rate is desired to make H<SUB>2</SUB> viable as cheap energy carrier. The process is influenced by C/N composition, pH levels, temperature, light intensity etc. In this study, Rhodobacter sphaeroides strain O.U 001 was used in the annular photobioreactor with working volume 1 L, initial pH of 6.7 +/- 0.2, inoculum age 36 h, inoculum volume 10% (v/v), 250 rpm stirring and light intensity of 15 +/- 1.1 W m<SUP>-2</SUP>. The effect of parameters, i.e. variation in concentration of DL malic acid, L glutamic acid and temperature on the H<SUB>2</SUB> production was noted using three factor three level full factorial designs. Surface and contour plots of the regression models revealed optimum H<SUB>2</SUB> production rate of 7.97 mL H<SUB>2</SUB> L<SUP>-1</SUP> h<SUP>-1</SUP> at 32 <SUP>o</SUP>C with 2.012 g L<SUP>-1</SUP> DL malic acid and 0.297 g L<SUP>-1</SUP> L glutamic acid, which showed an excellent correlation (99.36%) with experimental H<SUB>2</SUB> production rate of 7.92 mL H<SUB>2</SUB> L<SUP>-1</SUP> h<SUP>-1</SUP>.