Isolation decomposing bacteria of polycyclic aromatic hydrocarbons (PAHs) from Tashk Lake and examination of salt concentration effect on them

Abstract

Tashk Lake is located in the protected zone of the Bakhtegan Lake in the Fars Province and is a shelter for wildlife. This place is very important environmentally and ecologically. Among entering pollutants to this lake via rivers and side villages, polycyclic aromatic hydrocarbons (PAHs) compounds are noteworthy which are very harmful to humans and others creatures alike. We used naphthalene and anthracene as the only source of carbon to isolate PAHs degrading bacteria from three predefined stations. We found Pseudomonas sp. as the only PAHs degrading bacterium in the water and sediments of the lake. At the station 1 (Dehzir), the mean isolated bacteria acting on naphthalene and anthrecene were 27 and 23 in each ml of water and 57 and 47 in each gram of sediments, respectively. At the station 2 (Tashk), the mean isolated bacteria were 67 and 57 in each ml of water and 120 and 113 in each gram of the sediments which acted on the two carbon sources respectively. At the station 3 (Gomban), the figures were 127 and 113 for water and 163 and 147 for the sediments respectively.