基于均匀设计优化新鞘氨醇菌US6-1对高分子量多环芳烃的降解条件

Using Uniform Design to Optimize Degradation of High Molecular Weight Polycyclic Aromatic Hydrocarbons (HMW-PAHs) by Novosphingobium pentaromativorans Strain US6-1

运用均匀设计优化一株新鞘氨醇菌Novosphingobium pentaromativorans stain US6-1对芘、荧蒽、苯并[a]芘等高分子量多环芳烃(High molecular weigh polycyclic aromatic hydrocarbons,HMW-PAHs)的降解条件.结果表明,在最适生长条件(30℃、pH 6.5及NaCl浓度为2.5%)下,接种量与底物浓度是影响该菌降解能力的关键因素.在接种量D660 nm为0.6、芘初始浓度56 mg L-1、培养时间5 d的情况下,菌株US6-1对芘的降解达到32.5 mg L-1,预测平均准确率达99.38%;在接种量D660 nm为0.6、荧蒽初始浓度48 mg L-1、培养时间5 d的情况下,对荧蒽的降解达到34.3 mg L-1,预测平均准确率达99.61%;在接种量D660 nm为0.1、苯并[a]芘初始浓度60 mg L-1、培养时间为5 d时,对苯并[a]芘的降解达到24 mg L-1,预测平均准确率达98.75%.菌株US6-1对芘及苯并[a]芘的降解能力比未优化前分别提高了29.2%与58%.

The uniform design was applied to optimize the degradation of high molecular weigh polycyclic aromatic hydrocarbons（HMW-PAHs） by Novosphingobium pentaromativorans strain US6-1.It was found that inoculum size（D660 nm） and PAHs initial concentration were the critical factors under the optimal biodegradation condition（30 ℃,pH 6.5 and 2.5% NaCl）.The degraded pyrene was 32.3 mg L-1 within 5 days at the inoculum size of 0.6（D660 nm） and pyrene initial concentration of 56 mg L-1.The degraded amount of fluroanthene（34.3 mg L-1） reached largest after 5 days,when the inoculum size was 0.6（D660 nm） and fluroanthene initial concentration 56 mg L-1.Totally,23.7 mg L-1 benzo[a]pyrene was removed after 5 days with an inoculum size of 0.1（D660 nm） and benzo[a]pyrene initial concentration of 60 mg L-1.The verified experiment showed that the predicted degrading capabilities were fitted the optimum degrading capabilities very well,and the accuracy rate approached 99.38%,99.61% and 98.75%,respectively.It improved the abilities of pyrene and benzo [a] pyrene degradation by over 29.2% and 58%,respectively.It means that the biodegradation condition by strain US6-1 has been optimized initially.