A study of the effects of crude oil pollution and oil-degrading bacteria on some biochemical and growth factors of Zea mays

Bacteria-Plant systems for bioremediation of oil polluted sites are one of the most effective approaches of biotechnology in the recent years. It is well known that oil pollution induces oxidative stress in plants. In this research، the effects of crude oil pollution on Zea mays and bioremediation by synergism between plant and crude oil degrading bacteria، four different treatments were designed. Some physiological and microbial factors were assayed for determining the effects of oil pollution. The results showed that 1% crude oil in soil shoot، dry weight was reduced and the amount of phenolic compounds increased. With crude oil and Pseudomonas aeruginosa bacterium، shoot dry weight، chlorophyll (a)، total chlorophyll and anthocyanins decreased wherase phenolic compounds، malodialdehyde and catalase enzyme activity increased. With 1% crude oil and Acinetobacter calcoaceticus bacterium، significant changes were seen in the parameters of growth. Photosynthetic pigment did not increase whereas anthocyanin، phenolic compounds، malodialdehyde and catalase activity increased. White Crude oil and the presence of both bacteria shoot dry weight and chlorophyll levels decreased and increased levels of anthocyanin and malon-dialdehyde were observed. Addition of oil to the soil، increased the numbers of crude oil degrading bacteria and heterotrophic bacteria but crude oil were removed from soil by biodegradation. By application of bacterial-plant systems in the field، industrial wastes from refinery and biochemical factories could be removed oppropriately.