Diversity of culturable aerobic bacteria colonizing four petroleum by-products storage reservoirs

Abstract

The petroleum reservoirs are commonly exposed to bacterial contamination. The proliferation of several bacterial species, could modify the product quality, change viscosity, help other sulfatereducing, iron reducing bacteria to grow, and accelerate reservoir biocorrosion. Thus, companies of storage and transport of petroleum frequently use biocides to prohibit bacterial proliferation. However, the use of the appropriate biocide, need an obvious knowledge of bacterial population harbouring the reservoir. Thus, in this study, we intended to isolate and identify the aerobic bacterial population existing in different reservoirs of petroleum derivatives in the refinery of Bizerte, Tunisia. The isolation and identification of these microorganisms may be of great interest in bioremediation of polluted sites. Besides, it could inform about hydrocarbon specificity of these microorganisms and therefore lead to the use of suitable biocides to clean these storage reservoirs. 25 different bacterial strains were isolated from water collected from reservoirs of crude oil, gasoline, diesel oil and kerosene. The different strains were identified using morphological and biochemical characterization, as well as sequencing of 16S rRNA. The systematic study of these strains showed that they belong to six different genera. The highest strain number was affiliated to the genera of Pseudomonas and Bacillus followed by genera of Staphylococcus, Enterobacter Comamonas and Paenibacillus. The results of this study are discussed in terms of the ecological significance of these microorganisms in relation with physicochemical conditions of reservoirs and hydrocarbon composition.

The Influence of Stimulation Techniques on the Microbiological Changes and n-Alkane Transitions in the Soil Contaminated of Petroleum-Derived Substances

“…The transitions are accompanied with reaction changes both in the contaminated soil without any preparation as well as after adding it, what may be caused by the metabolic microorganisms activity (Krzyśko-Łupicka et al 2013, Rosik-Dulewska et al 2015 The vulnerability of n-alkanes on biodegradation depends on the chemical structure of hydrocarbons and their molecular mass; hydrocarbons degradation of the chains length C10-C22 takes place in the fastest way and the other groups characterized by high hydrophobicity are disintegrated in a much more difficult way (Dindar et al 2013;Hamed et al 2013). In our research, we have shown that the bioremediation stimulation with Fyre-Zyme preparation and with calcium carbonate was 084 p = ---p = 0.623 p = 0.991 p = 0.276 p = 0.916 Content of n-alkanes C 0.377 1.000 0.556 0.855 0.562 p = 0.623 p = ---p = 0.444 p = 0.145 p = 0.438 Content of n-alkanes FZ 0.009 0.556 1.000 0.609 0.997* p = 0.991 p = 0.444 p = ---p = 0.391 p = 0.003 Content of n-alkanes Ca 0.724 0.856 0.609 1.000 0.652 p = 0.276 p = 0.145 p = 0.391 p = ---p = 0.348 Content of n-alkanes FZ+Ca 0.084 0.562 0.997* 0.652 1.000 p = 0.916 p = 0.438 p = 0.003 p = 0.348 p = ---*Shown correlation significant at the level p < 0.05 leading to a decrease of long-chain hydrocarbons content (C28, C36, and C38).…”