
Full text loading...
Acinetobacter lwoffii strain ISP4 metabolizes isophthalate rapidly compared with Pseudomonas aeruginosa strain PP4 and Pseudomonas strain PPD. Isophthalate has been reported to be a potent competitive inhibitor of glutamate dehydrogenase (GDH). Exogenous supplementation of isophthalate with glutamate or α-ketoglutarate at 1 mM concentration caused strains PP4 and PPD to grow faster than in the presence of isophthalate alone; however, no such effect was observed in strain ISP4. When grown on isophthalate, all strains showed activity of NADP-dependent GDH (NADP-GDH), while cells grown on glucose, 2× yeast extract-tryptone broth (2YT) or glutamate showed activities of both NAD-dependent GDH (NAD-GDH) and NADP-GDH. Activity staining, inhibition and thermal stability studies indicated the carbon source-dependent presence of two (GDHI and GDHII), three (GDHA, GDHB and GDHC) and one (GDHP) forms of NADP-GDH in strains PP4, PPD and ISP4, respectively. The results demonstrate the carbon source-dependent modulation of different forms of NADP-GDH in these bacterial strains. This modulation may help the efficient utilization of isophthalate as a carbon source by overcoming the inhibitory effect on GDH.
Article metrics loading...
Full text loading...
References
Data & Media loading...