Phenol biodegradation by Bacillus spp. isolates from Kawengan Oil Well, Cepu

Abstract

Phenol is a toxic organic compound that potentially contaminates particular territorial water, decreases water quality, and disturbs territorial water ecosystem. The aims of this research were to find isolate of bacteria that able to degrade phenol and select them to obtain the best isolate on degrading phenol. The isolates used in this research were from Kawengan oil well in Cepu. It consist of 16 isolates of Bacillus spp. Five isolates were chosen based on its growth activity in a liquid mineral medium contained 100 ppm phenol. The optimum amount of phenol for the chosen isolates was determined by inoculating them in a mineral medium containing different amount of phenol. Growth curve was then constructed, and the ability of the isolate on decreasing phenol concentration in the mineral medium measured by using UV-VIS spectrophotometer. The result of the research indicated that the reduction of phenol taken place as a result of phenol biodegradation by 5 best isolates of bacteria. The decrease of the phenol concentration measured for 24 hours were: Bacillus sp 1 dcreased the phenol up to 214.21 ppm, Bacillus sp 4 up to 224.67 ppm; Bacillus sp 6 up to 217.28 ppm; Bacillus sp 8 up to 197.91 ppm; and Bacillus sp 12 up to 208,34 ppm subsequently. The isolate of Bacillus sp 4 indicated the highest ability of biodegradation that is can decreasing phenol equal to 56.17% during 24 hours.