Reiko Sashida

Microbial production of 2-hydroxynicotinic acid from nicotinic acid by intact cells of MCI3289

Abstract We investigated the microbial production of 2-hydroxynicotinic acid (2-HNA) from nicotinic acid (NA) by intact cells of MCI3289, which was isolated from soil by enrichment culture with 6-methylnicotinic acid as the sole carbon source. The strain which showed the 2-HNA-producing activity was revealed to be a member of the β-subgroup of Proteobacteria. The 2-HNA-producing activity was induced by the addition of 6-methylnicotinic acid and 2-hydroxy-6-methylnicotinic acid to the culture medium. Intact cells of this strain incubated at 30°C in an optimal reaction mixture containing 15 g/l of NA produced 6.40 g/l of 2-HNA for 29 h.

Production of (S)-(+)-citramalic acid from itaconic acid by resting cells of Alcaligenes denitrificans strain MCI2775

Abstract(S)-(+)-Citramalic-acid-producing activity in microorganisms was studied with resting cells in a reaction mixture containing itaconic acid. Itaconic-acid-utilizing bacteria were found to produce (S)-(+)-citramalic acid from itaconic acid. The strain, which showed the best productivity among those studied, was identified taxonomically as Alcaligenes denitrificans strain MCI2775. (S)-(+)-Citramalic acid produced by this strain was present in a 99.9% enantiometric excess. The culture and reaction conditions for the production were optimized for this strain. Addition of Mn2+, d-pantothenic acid and l-leucine to the culture medium enhanced the (S)-(+)-citramalic acid-producing activity. Under optimal conditions, 27 g (S)-(+)-citramalic acid/l was produced in 30 h. The yield to itaconic acid added was 69.0 mol%.