Glutamic acid racemase from Lactobacillus arabinosus.

The existence of a glutamic acid racemase activity in Lactobacillus arabinosus has been reported by Narrod and Wood (1) and by Ayengar and Roberts (2). As has been pointed out by Meister (3) these observations with dried cell preparations would not exclude a mechanism for glutamic acid racemization in which alanine racemase is coupled with n-glutamic acid-nalanine transaminase and n-glutamic acid-L-alanine transaminase, as has been shown to be the case for Bacillus subtilis (4). The purification of a single enzyme with glutamic acid racemase activity has not been previously reported. This paper presents a method of purifying glutamic acid racemase, and describes some of the properties of the enzyme.