ABSTRACT
Pollution of coastal marine ecosystems by Crude oil is a major environmental problem. The
North coast of Algeria is an example of a polluted ecosystem affected by petroleum pollution.
The physico-chemical characterization of the seawater taken from the harbor "Madrague" in
city of Ain Benian, showed a heavy contamination by organic and inorganic micropolluants.
The aim of this work was to investigate the criteria that allow a marine bacterium to degrade
hydrocarbons. 12 strains bacterial were selected in this study from a collection of 71 strains
isolated.
The biochemical characterization of the strains showed that 82% of the bacteria used are
Gram
-
, all the strains tested are catalase and oxidase positive exception of SS1B, ES2B, and
ES6B strains which are catalase negative and, also for ES2B, ES3B, ES5B, ES6B, ES8B
strains respectfully are oxidase negative. The majority of the isolates showed significant
biosurfactants production with important emulsification activities useful in biodegradation.
The results found for the drop collapse test were positive for the wells containing bacteria
SS2B, ES2B, ES3B, ES4B, ES7B with the exception of the blank which is devoid of bacterial
suspension and the wells containing bacteria SS1B, ES1B, ES5B, ES6B, SS3B, SS4B, ES8B.
This test only allows detection and not the quantification of biosurfactants.
The results obtained during the displacement test show that we have bacteria which were
considered to be strong producers of biosurfactants, the highly productive species which
showed a diameter of 2 cm or more during the oil displacement test were ES2B, ES3B, and
ES7B.Bacterial growth in the presence of different types of hydrocarbons shows that the
majority of bacteria are able to use these hydrocarbons as the sole carbon source. Aliphatic
hydrocarbons are rapidly and easily biodegraded compared to aromatic hydrocarbons. Our
overall results suggest that the obtained bacterial isolates may constitute potential candidates
for bioremediation and can be useful for biotechnological applications.
Key words: Crude oil, Marine bacteria, Hydrocarbonoclastes, strains, Biosurfactants,
Harbours, Marine pollution, Hydrocarbons, Biodegradation.
Pollution of coastal marine ecosystems by Crude oil is a major environmental problem. The
North coast of Algeria is an example of a polluted ecosystem affected by petroleum pollution.
The physico-chemical characterization of the seawater taken from the harbor "Madrague" in
city of Ain Benian, showed a heavy contamination by organic and inorganic micropolluants.
The aim of this work was to investigate the criteria that allow a marine bacterium to degrade
hydrocarbons. 12 strains bacterial were selected in this study from a collection of 71 strains
isolated.
The biochemical characterization of the strains showed that 82% of the bacteria used are
Gram
-
, all the strains tested are catalase and oxidase positive exception of SS1B, ES2B, and
ES6B strains which are catalase negative and, also for ES2B, ES3B, ES5B, ES6B, ES8B
strains respectfully are oxidase negative. The majority of the isolates showed significant
biosurfactants production with important emulsification activities useful in biodegradation.
The results found for the drop collapse test were positive for the wells containing bacteria
SS2B, ES2B, ES3B, ES4B, ES7B with the exception of the blank which is devoid of bacterial
suspension and the wells containing bacteria SS1B, ES1B, ES5B, ES6B, SS3B, SS4B, ES8B.
This test only allows detection and not the quantification of biosurfactants.
The results obtained during the displacement test show that we have bacteria which were
considered to be strong producers of biosurfactants, the highly productive species which
showed a diameter of 2 cm or more during the oil displacement test were ES2B, ES3B, and
ES7B.Bacterial growth in the presence of different types of hydrocarbons shows that the
majority of bacteria are able to use these hydrocarbons as the sole carbon source. Aliphatic
hydrocarbons are rapidly and easily biodegraded compared to aromatic hydrocarbons. Our
overall results suggest that the obtained bacterial isolates may constitute potential candidates
for bioremediation and can be useful for biotechnological applications.
Key words: Crude oil, Marine bacteria, Hydrocarbonoclastes, strains, Biosurfactants,
Harbours, Marine pollution, Hydrocarbons, Biodegradation.