Optimized growth of Rhodobacter sphaeroides OU001 using response surface methodology (RSM)

This study presents optimization of growth parameters (temperature, pH, ammonium conc. and inoculum size) to achieve an economical viable biohydrogen production process by Rhodobacter sphaeroides O.U.001 using response surface methodology (RSM) followed by analysis of light and agitation effects on bacterial growth using optimized conditions. Optimized growth conditions on third clay of fermentation, when R. sphaeroides O.U.001 was cultured aerobically under the presence of light (510 lux), were found as follows: temperature, 30.3 degrees C; pH, 4.71; ammonium conc., 0.60 g/l; and inoculum size, 6.02% (v/v). Light did not give a significant effect on overall growth of R. sphaeroides O.U.001. Agitation greatly influenced bacterial growth as a result of higher dissolved oxygen and dispersion of macromolecules in shake culture.