Abstract. An experimental study was carried out to investigate the effect of vitamin B-Complex on growth and l-glutamic acid accumulation by an auxotrophic mutant Micrococcus glutamicus AB100. Different concentrations (0.1 – 2.0 µg/ml) vitamin B12, Folic acid thiamine-HCl, riboflavin, nicotinic acid, pyridoxine-HCl, inositol, calcium pantothanate, paraamino-benzoic acid and biotin were examined. Production was maximum with vitamin B12, 1.0 µg/ml; Folic acid, 0.5 µg/ml; thiamine-HCl, 1.0 µg/ml; riboflavin, 0.5 µg/ml; nicotinic acid, 0.5 µg/ml; pyridoxine-HCl, 0.7 µg/ml; inositol, 0.6 µg/ml; calcium pantothanate, 0.4 µg/ml; paraamino-benzoic acid 0.3 µg/ml; and biotin 0.2 µg/ml. Production was decreased with further increment of the vitamin concentrations, but dry cell weight increased continuously with increased levels of the vitamins.
 

Keywords: Mutant, Micrococcus glutamicus, vitamin, dry cell weight.