Amino Acid Metabolism of Thermoanaerobacter Strain AK90: The Role of Electron-Scavenging Systems in End Product Formation

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 substrates	Amino acid (end of cultivation)	Branched-chain fatty acid	Methane
	Concentration (mmol/L)
T. brockii: leucine^#	1.5 ± 0.2	15.9 ± 2.3	9.3 ± 0.8
T. brockii: isoleucine^#	1.7 ± 0.3	15.4 ± 1.3	8.3 ± 0.8
T. brockii: valine^#	2.4 ± 0.2	14.8 ± 0.9	7.6 ± 1.0
T. ethanolicus: leucine	3.5 ± 0.3	15.0 ± 1.3	7.4 ± 1.1
T. ethanolicus: isoleucine	2.7 ± 0.4	14.3 ± 0.8	7.8 ± 0.9
T. ethanolicus: valine	12.4 ± 0.8	7.6 ± 0.6	3.4 ± 1.3