Alanine is produced by the transamination of one molecule of pyruvate using two alternate steps: 1) conversion of glutamate to α-ketoglutarate using a glutamate-alanine transaminase, and 2) conversion of valine to α-ketoisovalerate via Transaminase C.
Not much is known about the regulation of alanine synthesis. The only definite method is the bacteriums ability to repress Transaminase C activity by either valine or leucine (see ilvEDA' operon). Other than that, alanine biosynthesis does not seem to be regulated.