论文部分内容阅读
为解决精喹禾灵在环境中的残留,本实验以精喹禾灵为唯一碳源,采用富集培养法,从安徽省内受精喹禾灵污染土壤中分离到一株高效精喹禾灵降解菌(J-3),通过形态观察和16S rDNA序列分析,初步鉴定该菌株为红球菌属(Rhodococcus sp.)。菌株J-3在接种到LB液体培养基后,6 h进入对数生长期,18 h达到稳定生长期,48 h进入衰亡期。采用摇瓶振荡培养法,研究了温度、pH以及底物浓度对菌株生长能力和降解能力的影响,结果表明:菌株J-3生长和降解的最适温度为35℃,最适pH为8;在最适条件(精喹禾灵浓度100 mg/L,温度35℃,p H 8.0,接种量1%)下培养2 d可以达到98%以上的降解率。这也是首次报道红球菌属细菌对精喹禾灵降解特性的研究。通过LC-MS对降解产物进行鉴定,结果表明产物为精喹禾灵酸。基于以上研究认为,菌株J-3在精喹禾灵污染环境的生物修复方面具有潜在应用价值。
In order to solve the quizalofop-p-ethyl residues in the environment, we used quizalofop-p-ethyl as the sole carbon source and enriched culture method to isolate a high-efficient quizalofop-p-ethyl Degrading bacteria (J-3) were identified as Rhodococcus sp. By morphological observation and 16S rDNA sequence analysis. Strain J-3 was in logarithmic growth phase at 6 h after inoculation to LB liquid medium, reached a stable growth phase at 18 h, and entered the decay stage at 48 h. The shake flask culture method was used to study the effects of temperature, pH and substrate concentration on the growth and degradation of the strain. The results showed that the optimum temperature for the growth and degradation of strain J-3 was 35 ℃ and the optimum pH was 8. Under the optimal conditions (quizalofop-p-ethyl concentration 100 mg / L, temperature 35 ℃, p H 8.0, inoculum size 1%), the degradation rate was over 98%. It is also the first report of a study on the degradation of quizalofop-p-ethyl by Rhodococcus. The degradation products were identified by LC-MS. The results showed that the product was quizalofop. Based on the above studies, strain J-3 has potential application in the bioremediation of quizalofop-p-ethyl polluted environment.