PRODUCTION OF SUCCINATE FROM GLUCOSE, CELLOBIOSE, AND VARIOUS CELLULOSIC MATERIALS BY THE RUMINAL ANAEROBIC-BACTERIA FIBROBACTER-SUCCINOGENES AND RUMINOCOCCUS-FLAVEFACIENS

The production of organic acids by two anaerobic ruminal bacteria, Fib robacter succinogenes S85 and Ruminococcus flavefaciens FD-1, was comp ared with glucose, cellobiose, microcrystalline cellulose, Walseth cel lulose (acid swollen cellulose), pulped paper, and steam-exploded yell ow poplar as substrates. The major end product produced by F. succinog enes from each of these substrates was succinate (69.5-83%), the princ ipal secondary product was acetate (16-30.5%). Maximum succinate produ ctivity ranged from 14.1 mg/L.h for steam-exploded yellow Poplar to 59 .7 mg/L.h for pulped paper. For R. flavefaciens, the major end product from cellobiose, microcrystalline cellulose, and acid-swollen Walseth cellulose was acetate (39-46%), pulped paper and steam-exploded yello w poplar yielded succinate (42-54%) as the major product. Maximum succ inate productivity by R. flavefaciens ranged from 9.21 mg/L.h for cell obiose to 43.1 mg/L.h for pulped paper. In general, much less succinat e was produced at a lower maximum productivity by R. flavefaciens than by F. succinogenes under similar fermentation conditions. The maximum succinate productivities by these two organisms are comparable to the previously reported value of 59 mg/L.h for Anderobiospirillum succini ciproducens grown on glucose and corn steep liquor.