摘要

We investigated the effects of crude oil on the physiological responses of the cyanobacterium Anabaena sp. ISC55, based on growth, photosynthesis, chlorophyll a, phycobiliproteins, and nitrogenase activity. Additionally, the ability of this cyanobacterium to biodegrade crude oil was determined. Accordingly, Anabaena sp. ISC55, which was isolated from an oil polluted area, was treated with different crude oil concentrations (0; 0.5; 1; 2.5; 5, and 6%). Growth was determined by dry matter weight. Pigments were measured spectrophotometrically and photosynthesis determined by O₂ evolution. Nitrogenase activity was measured by acetylene reduction via GC. Our results showed that growth increased with higher concentrations of oil − except 6% oil. Photosynthesis activity of Anabaena sp. ISC55 decreased with increasing oil concentration. Chlorophyll a and phycobiliprotein contents were reduced with accretion of oil concentration. It was shown that nitrogenase activity was completely inhibited by adding crude oil to the cultures. With respect to biodegradation, the results suggested that Anabaena sp. ISC55 can reduce oil content by 8 and 53% after 14 and 28 days, respectively. Thus, our results confirm the ability of Anabaena sp. ISC55 to biodegrade oil and is a potentially valuable strain for further study.