This study on
d
-galacturonate metabolism by open, mixed-culture enrichments under anaerobic,
d
-galacturonate-limited chemostat conditions shows a stable and efficient fermentation of
d
-galacturonate into acetate as the dominant organic fermentation product. This fermentation stoichiometry and population analyses provide a valuable baseline for interpretation of the conversion of pectin-rich agricultural feedstocks by mixed microbial cultures. Moreover, the results of this study provide a reference for studies on the microbial metabolism of
d
-galacturonate under different cultivation regimes.