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

The effects of D-limonene and a-D-pinene on the in vitro dissimilation of carbohydrates and methane formation by rumen bacteria were studied by enrichment culture techniques. 9 10 -4 M D-limonene, but not 9 10 4 M a-D-pinene, was toxic to stabilized tureen cultures which produced methane from acetic acid. Methane production from formic acid by tureen cultures was not affected by these terpenes. Cellulose digestion, but not starch and ceUobiose dissimilation by tureen bacteria, was inhibited by higher concentrations of both terpenes. Editor.