Bacillus licheniformis coated bioparticles for hydrogen peroxide degradation

Abstract

The potential use of Bacillus licheniformis coated bioparticles for hydrogen peroxide (H2O2) degradation was assessed in this study. Bioparticles were made by mixing zeolite, activated carbon and cement in ratio 20:5:6 for attachment of biofilm. The efficiency of H2O2 degradation was examined in the presence and absence of biofilm (control) on bioparticles. Optimisation of biofilm development (7 and 10 days) and reusability were also investigated for H2O2degradation. Actively growing bacterial suspension (late exponential phase) of B.licheniformis was used in development of pure culture biofilm. The 7–day biofilm coated bioparticles system successfully achieved complete H2O2 degradation within an hour (highest rate = 1.17 % H2O2 degraded per minute) while the control showed no significant H2O2 degradation. After repeated use of biofilm coated bioparticles, the rate of H2O2 degradation declined to 0.654 % H2O2degraded per minute, and second use, the rate of H2O2 degradation was 0.166 % H2O2 degraded per minute. Field Emission Scanning Electron Microscope (FESEM) images of the biofilm coated bioparticles showed the attachment of cells and formation of extracellular polymeric substances (EPS), whereas the control showed no biofilm formed.