Affiliations: Key Laboratory of Terrestrial Ecological Process,
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016,
China | Graduate School of Chinese Academy of Sciences,
Beijing 100039, China | Key Laboratory of Environmental Engineering, Shenyang
University, Shenyang 100041, China | Institute of Microbiology, Chinese Academy of
Sciences, Beijing 100081, China
Abstract: Five dominant bacteria strains (Acetobacter sp., Alcaligenes sp.,
Micrococcus sp., Arthrobacter sp. and Bacillus sp.) and five fungi strains
(Cephalosporium sp. I, Cephalosporium sp. II, Aspergillus sp. I, Aspergillus
sp. II and Fusarium sp.) isolated from petroleum-contaminated soil were used to
assess the potential capability of mineral oil and PAH enhanced degradation
separately and jointly using the batch liquid medium cultivation with diesel
oil spiked at 1000 mg/L. The experiment was performed on a reciprocal shaker in
the darkness at 25°C to 30°C for 100 d. The dynamic variation in the
activity of microbial inoculators in each treatment and the degradation of the
target pollutants during the period of experiment were monitored. Results
showed a more rapid biodegradation of mineral oil and PAHs at the beginning of
the experiment (about 20 d) by dominant bacteria, fungi and their mixture than
that of the indigenous microorganisms, however, thereafter an opposite trend
was exhibited that the removal ratio by indigenous microorganisms was superior
to any other dominant treatments and the tendency lasted till the end of the
experiment, indicating the limited competitive capability of dominant
microorganisms to degrade the contaminants, and the natural selection of
indigenous microorganisms for use in the removal of the contaminants. At the
end of the experiment, the removal ratio of mineral oil ranged from 56.8% to
79.2% and PAHs ranged from 96.8% to 99.1% in each treatment by microbial
inoculators.
Keywords: dominant microorganism, indigenous microorganism, mineral oil, PAHs, biodegradation
