The role of viruses in contaminant biodegradation

• Applicant: Professorin Dr. Li Deng
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management ; Microbial Ecology and Applied Microbiology
• Term: since 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 273124240

Contamination with organic pollutants, such as petroleum hydrocarbons, is widespread in groundwater and a notorious threat to our water resources. Biodegradation is the single most important and sustainable process for contaminant breakdown. The biological activity that governed by numerous processes of which the current perspective is only evolving hydrology, biogeochemistry and environmental microbiology. One important piece of the puzzle, however, has been rarely touched: viruses. Viruses are ubiquitous and abundant global players that impact microbial communities through mortality and horizontal gene transfer to modulate microbial metabolism. During the last years diverse phenomena critical to the biology of microbes have been described to be driven by viruses, especially with respect to rapid environmental changes. The view that viruses are only parasites is no longer valid but viruses rather are able to transfer and store genetic information of their hosts and influence biogeochemical cycles in ecosystems. Consequently biogeochemical processes in microbial ecosystems and their potential for novel niche adaptation in response to changing environmental conditions can be understood only when this large dynamic gene pool carried by lytic and temporary viruses is recognized. However, little is known about this gene pool in groundwater ecosystem. This project now aims to elaborate a ground-breaking new perspective, the viral-driven degradation. I hypothesize that degradation of contaminants is greatly impacted by viruses through (i) horizontally transfer host metabolic genes related to contaminant degradation (hypothesis 1), and (ii) specifically lysing key bacterial degraders (hypothesis 2). In a cutting-edge and interdisciplinary research endeavor, I will verify the hypotheses using model aerobic and anaerobic degraders for the group of benzene, toluene, ethylbenzene and xylenes (BTEX) and polycyclic aromatic hydrocarbons (PAHs). Pillaring on my recent advance of methodology, the culture-independent, high-throughput approach Viral-Tagging which allows to link natural viruses to their hosts, and vice versa, carefully designed field surveys and microcosm experiments will be conducted to substantiate the hypotheses. The objectives of this project can revolutionize the current view on drivers behind the biodegradation. The generic mechanisms to be elaborated here have the potential to increase overall degradation activities, thus potentially opening new doors for bioremediation in the future.

• DFG Programme: Independent Junior Research Groups