during growth in the presence of 0.5-1.5 % alpha-aminobutyrate , both organisms accumulated high concentrations of isoleucine ( 100-225 microgram/ml ) while the normal accumulation of valine was unaffected . alpha-ketobutyrate , a product of alpha-aminobutyrate metabolism , also stimulated isoleucine excretion by these organisms .
C0025519
metabolism
C0221102
excretion