Optimization of Myo-inositol hexakisphosphate phosphohydrolase (MIPH) production and enhancement of hydrocarbons degradation by purified MIPH

Abstract

Objective: The present study characterizes bacteria with biodegradation ability and optimize the growth conditions of Myo-inositol hexakisphosphate phosphohydrolase (MIPH). Methods: Out of the 15 bacterial isolates, one strain SM01 showed the highest MIPH activity was selected based on the diameter of halo zone formation on calcium phytate plates. SM01 strain was identified as a Serratia marcescens with the highest phytate activity which was further confirmed by partial sequencing of the 16S rRNA gene. Results: MIPH enzyme was purified from Serratia strain which was found to exhibit a highly-specific MIPH activity and high specificity to the phytic acid but negligible activity against the other substrates tested. The purified MIPH enzyme had an isoelectric point of 6.8 and Molecular weight to 60 kDa. The degradative ability of Serratia marscescens shown that both the culture and the purified enzyme had maximum MIPH activity at the 36 h of incubation. 0.5 U/ml concentration of the purified MIPH enzyme was found to show similar activity as the 108 cfu/ml culture tested. Conclusion: Serratia marcescens SM01 strain was capable of degrading hydrocarbons due to their varied strategies to produce the MIPH enzyme. This could be made useful in the biodegradation of polluted soils and the environment.