In Vitro Biodegradation of Palm Oil Mill Effluent (POME) by Bacillus subtilis, Pseudomonas aeruginosa and Aspergillus niger

In vitro Comparison of Palm Oil Mill Effluent (POME) degradation was carried out using Bacillus subtilis, Pseudomonas aeruginosa and Aspergillus niger over a period of 16 days using POME as carbon source. pH, nitrate, phosphate, turbidity, and bacterial counts were carried out at intervals of 0, 4, 8, 12, and 16 days to assess the progress of degradation. There was appreciable increase in pH and turbidity in medium containing the organisms while phosphate and nitrate decreased with time. Colony counts showed a decline after day 8 in all organisms. The counts in P. aeruginosa and B. subtilis were higher than that of A. niger throughout the period of study. There were no significant differences (p>0.05) in the pH and nitrate while significant differences were observed in the turbidity, phosphate and colony counts at 5% probability level. Gas Chromatography Mass Spectrophotometric (GCMS) analysis carried out on days 0, 7, and 14 for Pseudomonas aeruginosa and Aspergillus niger showed decrease in peaks after day 7 while samples containing B. subtilis showed no reduction in peak numbers rather new compounds were formed in the process. At the end of the study, it was deduced that P. aeruginosa was able to efficiently utilize POME as a carbon source for growth better than Aspergillus niger and Bacillus subtilis and could play a great role in large scale treatment of palm oil effluent.