| An anthracene-degrading strain (A10) was isolated from contaminated environment and identified as Aspergillus fumigatus. The experimental results showed that the biodegradation rate of anthracene increased with the increasing time. Between 12-84 h interval, the biodegradation performed rapidly, while after this, the increase of biodegradation rate tended to become slow, and ultimately the biodegradation rate could achieve approximately 83%. The degradation rate of anthracene reached 79.37% within 5 days when the initial concentration of anthracene in mineral salts medium (MSM) was 10 mg/L, the inoculum dosage was 50 g/L (wet weight) and the cell age was 36 h. The concentration of anthracene had notable influence on degradation function of strain A10 and the highest degradation rate (92.17%) was achieved when anthracene concentration was 5 mg/L. The degradation rate could maintain about 60% with initial pH of MSM in the range of 5.0-7.5, and also, the anthracene could be better broken down when the temperature was 30℃ and dissolved oxygen was 4.30 mg/L. Certain amount of nutrition salts promoted the biodegradation of anthracene to some extent. Addition of lactose as co-metabolic substrate most favorably accelerated degradation of anthracene by about 37.15%. The mechanism research revealed that the biodegradation by strain A10 was a dynamic process in which extracellular sorption and intracellular degradation were included. FT-IR analysis exhibited that the structure of anthracene changed with the action of microbe, generating a series of metabolites, such as aromatic acid, aromatic ketone, aromatic aldehyde with one or two benzene rings, as well as saturated hydrocarbons. |
