Fig. 7From: Novel insight into the relationship between organic substrate composition and volatile fatty acids distribution in acidogenic co-fermentationThe synthetic pathways of propionate (a), valerate (b), butyrate (c), and acetate (d). Dotted arrows represent the transport pathway of substrate from extracellular environment to intracellular cytoplasm; solid arrows represent the synthetic pathway of single VFA. Arrows in different colors represent different synthetic pathwaysBack to article page