摘要
为获得苯并[a]芘(BaP)污染修复的新菌株,通过梯度提高无机盐培养基(MSM)中BaP浓度的方法,本研究从北京焦化厂污染土壤中筛选出1株能够对液体中高浓度BaP(100 mg/L)降解的霉菌,鉴定结果为可可毛色二孢菌(Lasiodiplodiatheobromae).并首次对L.theobromae在液体中降解BaP的性能进行了研究.结果表明,L.theobromae能够利用BaP作为唯一碳源和能源,实验进行10 d,BaP降解率为52.5%±1.5%.与察氏无机盐体系(CMM)相比,MSM更适合L.theobromae的生长,后者比前者中BaP的10 d降解率高2.8个百分点,MSM中加入土豆培养基(PDA)在降解初期显著提高了BaP的降解速率,第2 d时BaP降解率提高了19.2个百分点;但后期促进效果减弱,10 d后BaP降解率比单纯MSM体系高5.4个百分点.L.theobromae可耐受较广的pH范围,在pH=5时对BaP的降解率最高.底物水杨酸和琥珀酸钠促进了L.theobromae对BaP的降解,10 d降解率分别提高了6.2个百分点和4.2个百分点.L.theobromae同样能降解高浓度的菲和芘,三者单独和混合加入时,10 d的降解率分别是70.0%±1.0%、59.2%±3.2%和52.5%±1.5%,及21.6%±2.1%、14.5%±5.5%和11.9%±2.2%.对三者的降解能力:菲>芘>BaP,但是三者混合存在时,单个多环芳烃的降解率均降低.本研究为环境多环芳烃污染修复提供了新的修复菌种.
One new mycete,which could degrade high concentration（up to 100 mg/L） of benzo[a]pyrene（BaP） in liquid,was isolated from contaminated soil of Beijing Coking Plant by gradually increasing the concentration of BaP in mineral salt medium（MSM） in order to get new microorganism species for remediation of BaP contamination.The strain was identified as Lasiodiplodia theobromae,and its biodegradation ability in liquid was further investigated.The results showed that L.theobromae could utilize BaP as sole carbon and energy sources.The experiment was conducted for 10 days,and the biodegradation rate of BaP was 52.5%±1.5%.Compared to Czapek＇s mineral medium,MSM was more suitable for L.theobromae,and biodegradation rate was 2.8 percent greater than that by using Czapek＇s mineral media after 10 days＇ cultivation.Potato-dextrose nutrient medium could accelrate the biodegradation in early stage,and biodegradation rate of BaP increased by 19.2 percent in the second day.However,the accelration was not significant in the latter period,biodegradation rate was only increased by 5.4 percent after 10 days＇ cultivation.L.theobromae could tolerate a wide pH range,with the optimum pH of 5.Addition of salicylic and sodium succinate enhanced the biodegradation rates by 6.2 percent and 4.2 percent,respectively,after 10 days＇ cultivation.Besides BaP,L.theobromae could also degrade high concentration（200 mg/L） of phenanthrene and pyrene,and the biodegradation rates were 70.0%±1.0%,59.2%±3.2%,and 52.5%±1.5% when they were single substrate and were 21.6%±2.1%,14.5%±5.5%,and 11.9%±2.2% when they existed in mixture,respectively.The biodegradation rate followed an order of phenanthrene pyrene BaP.The co-existence of the three substrates led a reduction in biodegradation.This study provides a new microorganism species for remediation of polycyclic aromatic hydrocarbons（PAHs） contamination in the environment.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2011年第9期2696-2702,共7页
Environmental Science
基金
国家高技术研究发展计划(863)项目(2008AA06Z333)
国家自然科学基金项目(20907024)
天津市基础研究重点项目(10JCZDJC24200)
