STUDIES ON THE FERMENTATIVE PRODUCTION OF L-PROLINE

II. CONDITIONS FOR L-PROLINE PRODUCTION BY BREVIBACTERIUM FLAVUM 2247 No. 14-5

Abstract

L-Proline production by an isoleucine auxotrophic mutant No. 14-5 (ATCC No. 15940), derived from glutamic acid-producing strain of Brevibacterium flavum 2247, was investigated.
This strain produces a large amount of L-proline under vigorous aeration at 31° in a pH range from 7.0 to 7.5.
Among various substances supplemented to the medium, the following substances are found to enhance L-proline production: (1) divalent cations, such as Fe⁺⁺, Mn⁺⁺, Zn⁺⁺, and Mg⁺⁺ (at rather high concentration); (2) organic acids related to the TCA cycle, and tartaric acid; (3) some organic nutrients, such as meat extract, "Ajieki" polypeptone, and yeast extract; (4) amino acids, such as L-histidine, L-tryptophan, L-tyrosine, L-phenylalanine, glycine, L-serine, L-cystine, L-cysteine, and L-ornithine.
This microorganism is found to lack the threonine dehydratase activity, and a possible relation of the deficiency in threonine dehydratase activity in glutamic acid-producing bacteria to the abundant production of L-proline was discussed.