Skip to main content

Table 1 Volatile fatty acids production (VFA) and reductive process in the rumen adopted from [95, 96]

From: Dietary manipulation: a sustainable way to mitigate methane emissions from ruminants

Substrate

 

Products

∆G (KJ)1

Reactions

VFA production

 C6H12O6 + 2H2O

→

2 C2H4O2 + 2 CO2 + 8H+

 

Acetate production

 C6H12O6 + 4H+

→

2 C3H6O3 + 2 H2O

 

Propionate production

 C6H12O6

→

C4H8O4 + 2 CO2 + 4H+

 

Butyrate production

Reductive process

 CO2 + 4H2

→

CH4 + 2 H2O

− 67.4

Methane production

 2 CO2 + 4H2

→

C2H4O2 + 2 H2O

−8.8

Reductive acetogenesis

 SO42− + 4H2 + H+

→

HS− + 4 H2O

− 84.4

Sulfate reduction

 NO3− + 4H2 + 2H+

→

NH4 + 3 H2O

− 371

Nitrate reduction

  1. 1under following rumen conditions: H2 = 162 pa; pH = 6.5; [H2O] = 50 M; [succinate2−] = 4 × 10− 6 M; [malate2−] = [β-hydroxybutyryl-CoA] = [butyryl-CoA] = 10− 6 M; [acetate−] = 70 mM; [propionate−] = 25 mM; [butyrate−] = 15 mM; [lactate−] = 1 mM; [NH4+] = 11 mM (20 mg/dL); [HS−] = 0.14 mM. ∆G = free energy change indicates how energetically favourable it is i.e. the higher ∆G, the more energy utilization and negative ∆G indicates the energy release