Effects of D-Limonene and α-D-Pinene on in Vitro Carbohydrate Dissimilation and Methane Formation by Rumen Bacteria

Summary 9×10 −4 M d-limonene, but not 9×10 −4 M α-d-pinene, was toxic to stabilized rumen cultures which produce methane from acetic acid. Methane production from formic acid by rumen cultures was not affected by these terpenes. Cellulose digestion, but not starch and cellobiose dissimilation by rumen bacteria, was markedly inhibited by higher concentrations of d-limonene or α-d-pinene.