Antifoaming agent for fermentation, L-amino acid-producing medium and production process of L-amino acids

摘要

Disclosed herein are antifoaming agents for fermentation which include, as active ingredient at least one of (a) a reaction product obtained by adding at least one alkylene oxide to a mixture of a fat and/or oil with a trihydric or still higher polyhydric alcohol, or (b) a compound represented by the following general formula (1): ##STR1## wherein n stands for a number of 2-50, R.sup.1, R.sup.2 and R.sup.3 mean individually a hydrogen atom or an acyl group having 2-31 carbon atoms, x denotes an alkylene group having 2-4 carbon atoms, and m1, m2 and m3 are individually a number of 0-200, an L-amino acid-producing medium containing either one of these components, and a production process for L- amino acids making use of this medium. The use of this antifoaming agent permits the quick, sure and durable suppression of bubbling during incubation, and the overall production of the L-amino acid is significantly improved.