A Study On Effective Degradation Of Oil By Microorganism In Dontaminated Soils

With the development of modern biotechnology,more and more microorganism is used in environmental protection.The screening and determinant of microbial for oil degradation,the characteristic of strain S92,the biotransformation conditions of oil degradation,and the mechanism of Strain S92 and the soil bioremediation by microorganism were investigated.Several sorts of strains were isolated from samples by a series of experiments, 13 of them proved to be satisfactory effect on oil degradation were obtained.The best strain,named as S92 in this paper,with a higher oil degradation efficiency,was identified Pseudomons.S92 was mutagenized to S-3-15 by ultraviolet radiation.The optimum conditions for oil degradation was as follows:ratio of solid to liquid 2:5,inoculation capacity 20%,temperature 37℃,shaking table rotating speed 150 r/min,and aerobic cultivation for 15 d.Under these conditions,an oil degradation rate of 96.1%was gained by using S-3-15.The nutrient balance and mechanism were studied for enhancing the bioremediation of petroleum contaminated soils.The results show that the suitable condition was inoculation to sample at 1:45,And at a rotating speed of 150rpm,30℃of temperature,and 15d for cultivation,the weight ratio of N and P element in the nutrient is 4:1.The effects of different conditions on the bioremediation were studied.The results show that.During the process of 15-day bioremediation,bioaugmentation improved the degradation rate by 94.2%compared with that in nature condition. Microorganism will be more active with the increase of temperature,so does the degradation rate;adding nutrition and oxygen content will also be contributed to microorganism growth and in the end enhance the biodegradation.Therefore,with the advantage of low energy waste,higher efficiency, non-poisonous,harmless and non-secondary pollution,the microorganism oil degradation for polluted soil by oil is worth regarding and a further research.