Table 3.

Combination of populations used in the propionate degradation batch experimenta

Expt no.Digester inoculum vol (ml)Formate enrichment vol (ml)Acetate enrichment vol (ml)Anaerobic medium vol (ml)Initial formate activity (mg/liter · h)Acetate activity (mg/liter · h)Measured Propionate activity (mg/liter · h)ΔG′ (kJ)
11045213.98.313.4 ± 1.2
22035427.911.512.7 ± 2.0
330256311.813.612.4 ± 1.7
440158415.714.212.7 ± 2.1
5201025507.912.212.4 ± 1.3
6202015597.911.112.8 ± 1.7
720305677.911.113.2 ± 2.7
82010254313.913.113.0 ± 0.7
92020154519.914.415.5 ± 1.1
10203054625.913.118.5 ± 2.3
1120201055313.913.614.9 ± 1.7
1220102056019.914.416.6 ± 2.1
  • a Acetate activities were estimated from the average values obtained from the previous batch experiment, and propionate degradation was calculated from the experimental data.