Investigation of bioremediation potential and biopolymer production of Pseudomonads isolated from petroleum hydrocarbon-contaminated areas Background: Bacteria are diverse and abundant in soils, but only a few bacteria have known to growth on hydrocarbon contaminated areas and utilize complex carbon source such as crude oil for the synthesis of Polyhydroxyalkanoate (PHA) (bioremediation potential and the ability to produce important biopolymer). Bioremediation is the conversion of chemical compounds by living organisms, especially microorganisms, into energy, cell mass and biological waste products. Some of the most important of these bioremediation products are PHA, which are a family of biopolymers produced by some bacteria and accumulated intracellularly as carbon and energy storage material. Objectives: The main objective of this study was to investigate bioremediation potential and biopolymer production of Pseudomonads isolated from petroleum hydrocarbon-contaminated areas of different regions of Iranian South-Western refineries. Methods: From 45 isolated Pseudomonads, Fifteen PHA-producing strains were identified and their morphological, physiological, genomic, and 16S rRNA gene sequence properties were studied. Screening for PHA production was carried out by incubating the isolates in PHA production medium supplemented with 2% (v/v) Gachsaran crude oil. The repeated monomer composition of the copolymer was determined by GC–MS. Conclusion: Approximately 1/3 of the isolates were able to produce PHA using petroleum as a carbon source and produced biopolymer composites contained monomers of: C8 (3-hydroxyoctanoate), C10 (3- hydroxydecanoate), C12 (2-hydroxydodecanoate), C14 (3-hydroxytetradecanoate) and C16 (3- hydroxydecahexanoate) which are known as biopolymers. This study indicates that stressed environments like oil-contaminated sites can be potential sources for PHA producers and these isolates could be used in future bioremediation of hydrocarbons.
