Fate of antimicrobial reagents and the development of antibiotic resistance in the environment
Wastewater treatment plants (WWTPs) receive a large amount of antimicrobial reagents, including antibiotics from households and hospitals. The discharge of intact or partially metabolized antimicrobial micropollutants from WWTPs into the receiving aquatic environments raise emerging concerns about the potential development of antibiotic resistant bacteria (ARB) or genes (ARG), which will impose big risks to ecosystems and the public health. The occurrence and fate of antimicrobial reagents and the presence of ARB/ARGs in natural and built environments have been widely investigated, usually in different studies. The correlation between those two in the same sampling campaign has not yet been systematically explored.
In order to help protect the environmental and human health by providing more fundamental bases, this project is aimed to address the following research questions: 1) whether and how the presence of antimicrobial micropollutants affect the distribution of ARB/ARGs; 2) whether the presence of certain types of ARB/ARGs is associated to the biotransformation of specific antimicrobial compounds; 3) how the ARGs are distributed along the transport route, and what are the important factors affecting the horizontal transfer of ARGs.
Application of Microbial Communities Connecting N- and C- Cycles
With the concept of developing green, renewable and sustainable water management, energy recovery in the form of biogas from direct anaerobic digestion of domestic wastewater has been proposed as a promising alternative wastewater treatment process. However, due to the high loading rate of domestic wastewater, the amount of dissolved methane discharged in the effluent can be considerably high (up to 36-41% of total methane produced), especially at lower temperatures as the solubility of methane increases. The emission of methane from effluents and the removal of ammonia are two critical issues, meaning that post-treatment for nitrogen removal will be needed.
Very recently, denitrifying anaerobic methane oxidizing (DAMO) Bacteria and Archaea have been identified. They were able to grow in co-culture with anaerobic ammonia oxidizing (anammox) bacteria amended with methane, ammonia and nitrate. This project is going to test the feasibility of combining DAMO Bacterea/Archaea to the one-stage partial nitritation-anammox for simultaneous methane and ammonia removal, optimize bioreactor configurations and operational parameters to carry out maximum efficiency. To better fulfill this goal, the ecological relationships among the key functioning members will be studied at systems level, using a suite of microbial molecular tools, including FISH-based techniques, quantitative PCR, stable isotopic probing and the cutting-edge high throughput sequencing.