Stoichiometry of pectin and glucose fermentation in Prevotella ruminicola

Abstract

Prevotella ruminicola is an important rumen pectinolytic bacterium. Strain 659 was grown anaerobically at pH 6.5 and temperature 39 degrees C in LF2 fermenters on media containing glucose or pectin (4 g/l) in order to determine its fermentation stoichiometry and growth parameters. Both substrates were utilized almost completely (> 90%). The growth on pectin was more rapid than on glucose. Pectin and glucose differed considerably in composition of fermentation end-products. Production of acetate was significantly higher when P. ruminicola 659 was grown on pectin, while production of other metabolites (formate, succinate, lactate) was lower than on glucose. Production of dry cell matter was significantly higher in cultures supplied with glucose. An increase in dry matter and protein yields calculated per carbon was not verified.