Aerobic growth of S cerevisiae on ethanol is simply describe

Aerobic growth of S. cerevisiae on ethanol is simply described by the following overall reaction: C_2 H_5 OH + a O_2 + b NH_3 rightarrow c CH_1.704 N_0.149 O_0.408 + d CO_2 + e H_2 O Determine the coefficients a. b, c, and d, where RQ = 0.66. Determine the biomass yield coefficient, Y_X/S, and oxygen yield coefficient, Y_X/O_2 (gdw/g O_2).

Solution

R.Q (R.Q = Volume of CO₂ exhaled/Volume of O₂ utilized)

a) Determine the coefficients a, b, c and d, where RQ = 0.66

ANS:   a = 2.917, b = 0.011, c = 0.075, d = 1.925 and e = 2.953

b) Determine the yield coefficients YX/S (biomass/ethanol) and YX/O2 (biomass/oxygen)

ANS: YX/S (biomass/ethanol) = 0.364 g cells/g ethanol

            YX/O2 (biomass/oxygen) = 0.0179 g cells/g O2