应用QC-PCR技术研究高效菌株Rhodococcus ruber Em1在废水处理中的作用

Function analysis of the effective strain Rhodococcus ruber Em1 in wastewater treatment system by quantitative competitive PCR

摘要:

应用竞争性定量PCR(QC-PCR)技术,对石化废水处理系统中投加的高效芳烃降解菌株Rhodococcus ruber Em1数量变化趋势及其作用进行了分析。持续5个月从处理系统中不定期采集活性污泥样品,进行Em1菌株定量测定和处理系统的效果分析。结果表明,基于16S rRNA基因的特异引物具菌种水平的特异性,用其扩增污泥总DNA,并对产物克隆测序,所扩增的产物中62.2%为Em1菌株16S rRNA基因片段。检测得到活性污泥样品中含Em1菌株数量范围为3.4×10⁵～4.3×10⁸CFU/g,表明所投加的高效降解菌在处理系统中长期稳定存活并繁殖;Em1菌量与COD去除量之间的相关性系数(R²)高达0.89,表明Em1菌量与系统的处理效果具有明显的正相关性。这些结果说明,投加的Em1菌株在高浓度多环芳烃等污染物存在的条件和复杂菌群环境中,仍能长期稳定地存活并繁殖,在废水处理系统中发挥重要的作用。

Abstract:

A quantitative competitive PCR (QC-PCR) system was developed to quantify the number and analyze the function of the Rhodococcus ruber Em1 strain in a wastewater treatment system in Nanchong oil refinery plant. Strain Em1 was able to degrade various kinds of hydrocarbons and aromatic compounds with high efficiency and produce bio-emulsifier, so it was introduced into the waste liquid petroleum-disposing system. The sediment samples were collected from the disposing system in the range of 5 months, and then the numbers of strain Em1 and degrading efficiencies were studied. The results showed that the primers based on 16S rRNA gene sequence of strain Em1 were specific at species level. The PCR products amplified from sediment total DNA with the specific primers were cloned and sequenced, in which 62.2% were the fragments of 16S rRNA gene of strain Em1. Furthermore, the number of Em1 strain ranging from 3.4×10⁵～4.3×10⁸CFU/g in the sediment samples were detected, which indicated that the strain Em1 added into purposely did exist stably and reproduced well in the waste-deposing system during a long period. The high relativity, with relative coefficient R² of 0.89, between Em1 cell number and the amount of COD (Chemical Oxygen Demand) removal proved that the strain Em1 played an important role in this bio-augmentation treatment system.