不同碳氮源对Paracoccus sp.QD15-1降解邻苯二甲酸二甲酯的影响

Effect of different carbon and nitrogen sources on degradation of phthalate degrading bacteria

邻苯二甲酸二甲酯(Dimethyl phthalate, DMP)是一种高毒性的有机污染物,Paracoccus sp.QD15-1能够高效降解DMP,碳氮源是微生物需求量最大的生长要素。本实验以Paracoccus sp.QD15-1为研究对象,在基础无机盐(MSM)培养基中分别外加不同碳氮源(碳源分别为5 g·L^-1的葡萄糖、蔗糖、乳糖和淀粉;氮源分别为5 g·L^-1的硫酸铵、硝酸钠、硝酸铵和尿素),研究Paracoccus sp.QD15-1生长和降解DMP能力的变化。结果表明,外加4种碳源后,菌株生物量和降解DMP能力均显著提高,其中外加淀粉处理的最大比生长率达到0.13 lg(cfu)·h^-1,36 h降解率为78.2%,DMP半衰期为15.6 h。外加4种氮源后,降解菌的生物量均有所上升,其中外加尿素,36 h降解率为62.8%。研究表明,Paracoccus sp.QD15-1在不同碳氮源中均能够较好地降解DMP,且外加淀粉作为碳源和外加尿素作为氮源的降解效果更佳,在实际工程应用中具有良好前景。

Dimethyl phthalate(DMP)is a highly toxic organic pollutant. Paracoccus sp.QD15-1 can degrade DMP efficiently. The carbon and nitrogen sources are the important nutrients for the growth of microorganisms. In this study, the growth and DMP degradation of Paracoccus sp.QD15-1 were detected in the basic inorganic salt medium by addition of different carbon and nitrogen sources. The results showed that the growth and capacity for degrading DMP of Paracoccus sp.QD15-1 were significantly improved by four carbon sources. With starch addition, the maximum specific growth rate reached to 0.13 lg(cfu)·d^-1, the degrading rate of DMP reached 78.2%, and half-life of DMP reached at 15.6 h. The biomass of Paracoccus sp.QD15-1 was improved significantly by the addition of nitrogen sources. With urea addition, the degrading rate of DMP reached 62.8% at 36 h. Therefore, the addition of carbon and nitrogen sources could improve the capacity of Paracoccus sp.QD15-1 for degrading DMP, and Paracoccus sp.QD15-1 would have good prospects in practical engineering applications.