Identification of Phenol-Assimilating Microorganisms under Aerobic Conditions in A Coke Oven Wastewater Treatment System by Comparative Stable Isotope Probing of RNA

Abstract

Stable isotope probing of RNA (RNA-SIP) was applied for the identification of phenol-assimilating microorganisms in activated sludge treating a synthetic coke oven wastewater. The RNA-SIP method is a culture-independent method using stable isotope-enriched substrates that be able to link the identity of microorganisms with their function in the environment. The activated sludge was fed with ¹³C-labeled phenol (300 mg per 1) and ribonucleic acids of phenol-assimilating microorganisms were labeled with ¹³C. The ¹³C-RNA was extracted from the samples, fractionated by ultracentrifugation, and analyzed by terminal restriction fragment length polymorphism, and the selected fractions were further analyzed by cloning and sequencing. These analyses showed that the bacteria assimilating ¹³C derived from the ¹³C-labeled phenol were the Betaproteobacterial Thauera genus, the Gammaproteobacterial Marinobacterium and Halomonas genera, and the Actinobacterial Propionibacterium genus.