1. Isolation and Evaluation of Bacteria Degrading Polycyclic Aromatic Hydrocarbon
for Future Bioremediation
The environment has become the current worldwide concern. PAHs are organic
pollutants which have accumulated in the environment and known to be toxic, mutagenic and
carcinogenic. The pollutants not only can lead to tumor but also have disadvantageous effects
on immunity, development and reproduction. PAHs are detected in Yatsushiro Sea, Japan,
consisting of high molecular weight (HMW) PAHs such as Fluoranthene (Fla), Pyrene (Pyr),
Benzo-bFluoranthene (BbFla) and Chrysene (Chry) with mean concentration 30,200 parts per
billion (ppb) dry weight, in which two highest concentration of PAHs are Fla and Pyr. This
concentration number is extremely very higher than 0.2 ppb, the maximum contaminant level
(MCL) for total PAHs has been established by the U.S. Environmental Protection Agency
(U.S.EPA). Due to their widespread distribution, the PAHs cause ubiquitous pollutants and
environmental problems, therefore, there is an urgent required to clean up pollutants. One of
the most technology widely used for breaking down the pollutants is bioremediation.
Bioremediation is a promising technology for cleaning up the polluted environment by using
microorganisms. The technique is better than other remediation technologies such as
chemical and physical remediation because of economical, efficient and friendly
enviromentally. For above consideration, the presense of the environment with very high
concentrations of HMW PAHs is an opportunity and at once a challenge how to find a proper
solution to the environmental problems, especially in order to trigger up the biodegradation
process by isolating and evaluating of bacteria degrading PAHs. The study had shown that
some PAHs-degrading bacteria can be isolated using a minimum medium from polluted
coastal environment. They were distributed into divergence four classes: β-proteobacteria, γ-
proteobacteria, α-proteobacteria and actinobacteria with 98 to 99% similarity. Meanwhile, the
investigation of the fluoranthene and pyrene degradation experiment showed that two isolated
strains close to B. fungorum and M. gilvum had great PAHs degradation, where they can
degrade the high concentration (100,000 ppb) of PAHs, even though using a limited medium.
The biodegradation demonstrated that almost the entire fluoranthene and pyrene can be
cleaved and utilized need 24 - 28 days and 16 - 20-day incubation of a period, respectively.
These isolated bacteria might be applied as PAHs degraders for future bioremediation on the
coastal sites polluted with PAHs.
Correspondence :
R.Darmawan
Department of Chemical Engineering - Institut Teknologi Sepuluh Nopember (ITS) Surabaya
Email : rdarmawan@chem-eng.its.ac.id