Table 2: Amino acid degradation and end product formation from branched-chain amino acids by Thermoanaerobacter brockii and Thermoanaerobacter ethanolicus in a coculture with Methanothermobacter strain M39. Initial amino acid concentration was 20 mM in all cases. Data represent the average of two replicate experiments ± standard deviation. The branched-chain fatty acids from leucine, isoleucine, and valine were 3-methylbutyrate, 2-methylbutyrate, and 2-methylpropionate, respectively. Data from [16].

Strain and substratesAmino acid (end of cultivation)Branched-chain fatty acidMethane
Concentration (mmol/L)

T. brockii: leucine#1.5 ± 0.215.9 ± 2.39.3 ± 0.8
T. brockii: isoleucine#1.7 ± 0.315.4 ± 1.38.3 ± 0.8
T. brockii: valine#2.4 ± 0.214.8 ± 0.97.6 ± 1.0

T. ethanolicus: leucine3.5 ± 0.315.0 ± 1.37.4 ± 1.1
T. ethanolicus: isoleucine2.7 ± 0.414.3 ± 0.87.8 ± 0.9
T. ethanolicus: valine12.4 ± 0.87.6 ± 0.63.4 ± 1.3