Microbial Degradation of Crude Oil by Acinetobacter baumannii T30c Isolated from Petroleum Hydrocarbon Contaminated Areas
Loading...
Date
2010-01
Authors
Chang, Lee Kok
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Bioremediation technology comes of age due to frequent occurrence of oil
pollution accidents which have caused ecological and social catastrophe. The aims of the
project were to isolate the potential hydrocarbon-degrading bacteria and to study a
biodegradation potential of the selected bacteria in a flask system, bioreactor system and
application of bacterial inoculum in the Tapis crude oil-contaminated soil. One of the
bacterial isolate, namely T30C was screened as potential hydrocarbons degrader.
Bacterial isolate T30C was identified as Acinetobacter baumannii by morphology
characterization, biochemical test, identification kit of RapiD™ NF Plus System (remel)
and molecular level identification of 16S rRNA. Crude oil biodegradation study of
Acinetobacter baumannii T30C with the following optimum condition of pH 8.0, 15 %
(v/v) of inoculum size, temperature of 37 °C and agitation rate of 200 rpm resulted the
maximum dry cell weight production of 0.12 g/L and percentage of crude oil
degradation of 20 % of 1 % of crude oil addition after optimization of physical
parameters. After optimization of chemical parameters on crude oil biodegradation study,
the bacterial growth of 2.20 giL of dry cell weight and crude oil biodegradation of 67 %
were obtained with the optimum medium composition as following: (NH4)2S04, 3 g;
KH2P04, 4 g; Na2HP04, 7 g; MgS04·7HzO, 0.2 g; CaClz·2H20, 0.001 g; FeS04·7HzO,
0.001 g; Tween 80, 4.0 g/L in 1 L of distilled water (MSM) added with 1.0 %(w/v) of
xxvii
Tapis crude oil. By monitoring the different levels of physical parameters of agitation
rate and flow rate in a stirred-tank bioreactor, maximum growth of 4.14 giL of dry cell
weight and Tapis crude oil biodegradation of 67 % was achieved at the condition of 400
rpm and 0.67 vvm, with supplementation of 2.5 % (w/v) of crude oil. Finally, the
sustainability growth of the bacteria isolate Acinetobacter baumannii T30C was tested,
which bacteria was augmented in Tapis crude oil-contaminated soil based on the viable
cell count and reduction of residual hydrocarbon extracted from the soil. Analysis of gas
chromatography-flame ionization detection (GC-FID) showed that most aliphatic
hydrocarbons (n-alkanes) were degraded extensively by bacterial isolate Acinetobacter
baumannii T30C.
Description
Keywords
Acinetobacter baumannii