Silica-immobilized Methylobacterium sp. NP3 and Acinetobacter sp. PK1 degrade high concentrations of phenol.

AIMS

To immobilize Methylobacterium sp. NP3 and Acinetobacter sp. PK1 to silica and determine the ability of the immobilized bacteria to degrade high concentrations of phenol.

METHODS AND RESULTS

The phenol degradation activity of suspended and immobilized Methylobacterium sp. NP3 and Acinetobacter sp. PK1 bacteria was investigated in batch experiments with various concentrations of phenol. The bacterial cells were immobilized by attachment to or encapsulation in silica. The encapsulated bacteria had the highest phenol degradation rate, especially at initial phenol concentrations between 7500 and 10000 mg l(-1) . Additionally, the immobilized cells could continuously degrade phenol for up to 55 days.

CONCLUSIONS

The encapsulation of a mixed culture of Methylobacterium sp. NP3 and Acinetobacter sp. PK1 is an effective and easy technique that can be used to improve bacterial stability and phenol degradation.

SIGNIFICANCE AND IMPACT OF THE STUDY

Wastewater from various industries contains high concentrations of phenol, which can cause wastewater treatment failure. Silica-immobilized bacteria could be applied in bioreactors to initially remove the phenol, thereby preventing phenol shock loads to the wastewater treatment system.