The Effect of Different Light Intensities on Physiological and Biochemical Responses in Cyanobacterium Schizothrix vaginata under Naphtalene Treatment

Petroleum hydrocarbons pollution is one of the problems in the environment due to petroleum industry processes. Biological methods are novel routs to defend against them. In this research, the effect of light intensities on biodegradation of naphthalene and the physiological responses of cyanobacterium Schizothrix vaginata is investigated. In this order, studied cyanobacterium transfered to liquid medium, after isolation in the solid BG11 medium. Following transferred to a liquid medium the alga was treated with naphthalene %0.05. OD, dry weight, chlorophyll, and phycobiliproteins were measured spectrophotometrically and naphthalene degradation was studied by gas chromatography (GC). Data obtained from physiological analysis were evaluated by historical data pathway via Design Expert software. According to the results, the maximum chlorophyll and phycobiliproteins contents belonged to 5000 lux. The reduction percent of Naphtalene also enhanced with increasing of light intensity and achieved its maximum in 3th hour. Dry weight reduced under naphthalene treatment by time, indicated negative effect of this pollutant on studied cyanobacterium. The obtained results suggest that microbial biodegradation of pollutants can be used to clean up contaminated environments. Biotreatment of wastes using living organisms is an environmentally friendly, relatively simple and cost-effective alternative to physico-chemical processes.