News & Events
Newly Characterised Microbes Respiring on Persistent Organic Pollutants - PCBs
Speaker(s): A/Prof. He Jianzhong, Department of Civil and Environmental Engineering, National University of Singapore
When: 16 August 2017 (2:00 - 3:00pm)
Where: SBS CR2 (Level 1)
Type: Seminars


Polychlorinated biphenyls (PCBs) as priority persistent organic pollutants (POPs) are ranked fifth on the U.S. Environmental Protection Agency Superfund Priority List of Hazardous Compounds. PCBs were massively produced and sold as complex mixtures (e.g. Aroclor 1260) for industrial usages, resulting in their widespread distribution in sediments of lakes, rivers and harbours. Although the PCB detoxification through microbial reductive dechlorination has been studied for more than 20 years, the difficulty in cultivating PCB-dechlorinators in pure culture impedes further characterisation, optimisation, and application in in situ bioremediation. By combining traditional culture techniques with next-generation sequencing technology, we successfully cultivated and characterised three PCB-respiring Dehalococcoides in pure culture and identification of their key functional genes. By pre-growing Dehalococcoides in tetrachloroethene (PCE), extensive dechlorination of PCB congeners in Aroclor1260 could be achieved within one week, which is much faster than previous reports of months to years. Discoveries of this study advance bioremediation of PCBs in the polluted environment.


Dr. Jianzhong He is an associate professor at NUS and her research focuses on discovering novel microorganisms to transform and detoxify environmental contaminants, enhancing biodegradation, and applying nucleic acid-based approaches in laboratory cultures and in situ. She received her Ph.D. degree at the Georgia Institute of Technology in 2003 from Professor Frank Löffler’s lab. Prior to that, she obtained her M.S. and B.S. degrees from Tsinghua University and Harbin Institute of Technology in 1998 and 1995, respectively. She was a postdoctoral researcher in Professor Lisa Alvarez-Cohen’s lab at the University of California at Berkeley for two years before joining NUS as an assistant professor in 2005. During her tenure at NUS, Jianzhong has generated 67 peer-reviewed publications while securing significant amount of external funding from diverse funding agencies (>$15 million in the past 10 years). So far, her publications have been cited for more than 2100 times (Web of Science) and an H-Index of 20. She holds several patents and collaborates widely with industrial, governmental and scientific partners. She is also an editorial board member of the Journal of Scientific Reports, the ISME Journal, and Applied and Environmental Microbiology.