Fig. 3

Real-time PCR analysis of gene transcripts involved in hydrolysis and solventogenesis. Changes were illustrated for selected genes of Clostridium sp. strain BOH3 at 36 h of fermentation (at the end-exponential phase) with or without CaCO₃. Relative expression levels confirmed the upregulation of amyA and amyB encoding α-amylase (α-AMY), bdhA, bdhB, and bdhC encoding butanol dehydrogenase (BDH), and down-regulation of aadB encoding alcohol/aldehyde dehydrogenase (AAD), and adc encoding acetoacetate decarboxylase (AADC)