Study On Characteristics Of Degradation Of Aureomycin By The Monascus B₃

In connection with two major difficulty points of high antisepsis and difficult degradation of the aureomycin wastewater, the fungi had been screened to degrade aureomycin effectively. Based on this, the experiments were went on to study on the strain's characteristics of the cell growth and degradation of aureomycin under the host condition, and to determine the optimum condition that promoted aureomycin degrading, which could be the essential theoretical foundation for biological treatment of aureomycin wastewater. Eight fungal species, which had the ability to tolerate high concentration of aureomycin, were isolated from activated sludge by enrichment and adaptation culture technique. A special strain B3 with high aureomycin degrading ability was isolated in the further screen, which was identified as Monascus. The optimal temperature, pH value and phosphate concentration for the cell growth and degradation of aureomycin was 30℃ , 6.0, and 0.200g/L, respectively. The aureomycin concentration that the Monascus B3 could endure was up to 4000mg/L. When aureomycin was supplied as the sole source of carbon, nitrogen, the growth of the strain B3 and degradation of aureomycin were slow. In contrast, the supplementary apply of glucose, saccharose, maltose, glycerol and ammonia sulfate could promote the cell growth and degradation of aureomycin obviously. The Monascus B3 could use antibiotics wastewater as energy material for its growth, the rate of removal of CODCr could be up to 67.6% after three days. When aureomycin and glucose coexisted, the Monascus B3 showed the typical catabolic characteristic to utilizate aureomycin and glucose sequentially. In the present of aureomycin and glucose, strain B3 used glucose as metabolize material for growth preferentially. After the concentration of glucose was declined to 0.1g/L, aureomycin began to be degradated by the strain B3 obviously. The data of Fed-Batch experiments showed that the optimal dosage ratio of glucose and aureomycin was 4~6. The data of Fed-Batch experiments showed that concentrations of aureomycin had significant effects on the rate of the cell growth and degradation of aureomycin. Under the relatively low concentration range of aureomycin (50~500mg/L), the increase of concentration could promote the cell growth. The optimal concentrations for its degradation were 1000~1500mg/L. However the concentration of aureomycin greater than 2000mg/L was showed obvious inhibition to the growth and the degradation. When aureomycin waste water was accident discharged, it had great effect on the sewage treatment system. Adding powder activated carbon on 100 mg/L and the Monascus B3 on 2% could efficiently eliminate the impact load caused by aureomycin, and stabilize the system.