Isolation and Identification of Carbazole Degrading Bacteria from Lake Water

Abstract

Heterocyclic hydrocarbon compounds have been identified as one of the major components of water pollution that occurs as a result of urbanization. It has been known that the presence of these compounds is hazardous and remain in the environment for a long period of time. This study was conducted to isolate and identify heterocyclic hydrocarbon degrading bacteria from lake water by genomic DNA extraction and sequencing as well as measure the degradation rate of the bacteria using Gas Chromatography Flame-Ionization Detector (GC-FID). The water sample was collected from west campus lake of Universiti Malaysia Sarawak where six strains of bacteria that has degrading ability was isolated using sub-culturing technique on MSM double layer agar plates. The genomic DNA of bacteria designated as strain IM1, IM2, IM3, IM4, IM5 and IM6 were extracted and amplified using Polymerase Chain Reaction (PCR). The isolates were then sequenced and were identified as Bradyrhizobium sp., Ochrobactrum sp., Pseudomonas aeruginosa sp. and Burkholderia sp. All six isolates possessed the ability to utilize carbazole as sole carbon and energy source as the degradation rate of carbazole was measured using GC-FID analysis. After 12 days of incubation, IM2 showed 96.37% degradation while the other five isolates were able to degrade 100% of the carbazole. Thus, bacteria isolated from this study may provide great benefit for bioremediation.