Kinetics of p-nitrophenol degradation by Pseudomonas pseudomallei wild and mutant strains

Abstract

Pseudomonas pseudomallei EBN-10 strain, previously isolated from a local pharmaceutical industry's wastewater, was spontaneously adapted to higher p-nitrophenol (PNP) levels, which then was subjected to gamma ray-induced mutagenesis; the efficient isolates hence obtained were designated as EBN-11 and EBN-12, respectively. EBN-12 mutant strain could completely mineralize PNP (100 mg/L) on the minimal media in 24 h while, the parent strain utilized only 6% of it. Addition of glucose as co-substrate further increased the PNP degradation rate; however, phenol inclusion inhibited the degradation process. Ammonium sulphate was experienced as the best of the nitrogen sources used by EBN-12 mutant strain, while degrading PNP.

Keywords:

• Adaptation
• biodegradation
• kinetics
• p-nitrophenol
• Pseudomonas pseudomallei

Acknowledgments

The authors acknowledge Dr. M.I. Rajoka, S.I., Deputy Chief Scientist, NIBGE, for some valuable suggestions. Ms. Asma Rehman is highly indebted to Ms. Javaria Qazi, Research Scientist, NIBGE for her constant encouragement throughout her research.

Notes

*Glucose (100 mg/L) was added as co-substrate.

**Phenol (100 mg/L) was added as co-substrate.