Studies on dl-Alanine Formation by Thermophilic Bacteria

During the course of the screening of thermophilic microorganisms, several strains were found to accumulate amino-acids. Of those strains that were isolated from feces source with Bennett medium, one strain was found to produce a large amount of an amino acid. This amino acid was isolated in crystalline form and identified as dl-alanine by IR absorption spectrum, specific rotatory power and elementary analysis. The taxonomic studies were carried out and this strain was identified as Bacillus coagulans. The strain B. coagulans B₉-17 produced dl-alanine as much as 1000 mg/l after 24 hours at 50°C in shake culture.

The yield of dl-alanine was increased up to 16.5 g/l with some improvements.