although the maximum volumetric production rate achieved when using RPS hydrolysate (3.0 g L−1 h−1 ) is somewhat lower than the one obtained with commercial sugars (4.0 g L−1 h−1 ), a significantly higher lactic acid concentration was achieved on hydrolysate. Indeed L. rhamnosus produced 61.1 g L−1 (after a 168-h cultivation) of lactic acid on RPS hydrolysate comparatively to the concentration of 53.9 g L−1 achieved on the control fermentation (after 24 h).