Evidence for auxotrophic nature of Corynebacterium glutamicum X680
*Subhadeep Ganguly
Department of Physiology, Vidyasagar College, 39, Sankar Ghosh Lane, Kolkata-700006 (India) *Address for correspondence: res_biol@rediffmail.com
ABSTRACT
The present investigation was undertaken to determine the specific nutritional deficiency of the newly developed mutant Corynebacterium glutamicum X680 maintenance of its L-glutamic acid over production. In this connection, I added cyanocobalamin, folic acid, thiamine-HCl, riboflavin, nicotinic acid, pyridoxine-HCl, inositol, calcium pantothanate, paraamino benzoic acid (PABA) and biotin one by one in the minimal salt medium (2μg/ml each) to evaluate their specific requirement for this mutant. The mutant showed nutritional requirement for biotin only.Various concentrations of biotin were tested. The mutant required biotin auxotroph with 3 μg/ml. Different kinetic parameters like rate of product yield (qp), specific product yield (Yp/x) and rate of glucose consumption (Yp/s) were studied. Production of L-glutamic acid decreased significantly (p<0.01) above and below this concentration. The growth pattern and productivity varied with different concentrations of biotin. Conclusion: The mutant strain proved to be a biotin auxotroph.