Continuous solvent production from whey permeate using cells of Clostridium acetobutylicum immobilized by adsorption onto bonechar

Cells of Clostridium acetobutylicum were immobilized by adsorption onto bonechar and used in a packed bed reactor for the continuous production of solvents from whey permeate. A maximum solvent productivity of 4.1 g l −1 h −1, representing a yield of 0.23 g solvent/g lactose utilized, was observed at a dilution rate of 1.0 h −1. The reactor was operated under stable conditions for 61 days. High concentrations of lactose in the whey permeate favored solventogenesis, while low concentrations favored acidogenesis.