Bioremediation of crude oil and its effect of residue in growth of wheat plants

Abstract

Three strains of bacteria were studied to bioremediation crude oil in soil and in the laboratory. These bacteria were Azospirillum spp., Azotobacter spp. And Rhizobium spp. The results showed that Azospirillum spp. , Rhizobium spp. was more efficiency to bioremediation crude oil than Azotobacter spp., also the results showed that the higher number of bacteria was recorded in soil treatment with Rhizobium spp. in presence of crude oil in first week , and the number of this bacteria reached to 22.6 x 108 , but the lowest number of bacteria was recorded in soil without added crude oil (control), and the number reached to 2 x 107.The statistical methods obtained that no significant were recorded between different treatments . Also, the results showed that the numbers of bacteria in soil treatment with crude oil were decreased regularly from second week until ten weeks. The results showed that the height of the aerial parts of wheat plants reached to 73 cm in soil treatment with Azotobacter spp. And crude oil after 10 weeks, and the lower length reached to 47 cm. At the same time the results obtained that the higher wet weight of wheat plants was reached to 56 gm in soil treatment with Rhizobium spp., and in the presence of crude oil after 10 weeks, but the lower wet weight was reached to 25 gm in control. Also, the results showed that the higher of dry weight of wheat plants was reached to 23 gm in soil treatment with Rhizobium spp. and in the presence of crude oil after 10 weeks, but the lower dry weight was reached to 10 gm in control, however the statistical methods that no significant were recorded between the different treatments. Also, that all these bacteria have ability to removal crude oil in soil and in mineral salts medium.