Jozef Nissimov

• virus ecology
• comparative genomics of aquatic viruses
• host-virus infection dynamics
• microalgal biology and physiology
• biological oceanography

Dr. Nissimov’s work range from studying the effects of virus genomic and functional variability on their virulence, the physiological responses of infected cells to infection, the effects of environmental conditions on host susceptibility to infection and virus success, and the extent to which virus-infection influences host ecology and, by extension, the fate of cell-associated organic and inorganic matter. Other aspects of Dr. Nissimov’s work are the study of the evolutionary relationships of algal viruses with their unicellular hosts and other taxa on the tree of life.

The approach that Dr. Nissimov undertakes is multifaceted. It includes laboratory experiments using controlled environment chambers and photo-bioreactors, and studies in the field, where hosts and viruses naturally co-occur. Indeed, Dr. Nissimov has studied microbial interactions and their diversity in the field through work he has done on oceanographic cruises in remote locations in the North Atlantic, South Atlantic, and Pacific Oceans, a sampling campaign in Antarctica, and mesocosm experiments in The Arctic Circle and the fjords of Norway.

The main viruses used in Dr. Nissimov’s work are large dsDNA viruses infecting coccolithophores, small ssDNA and ssRNA viruses infecting diatoms, and large dsDNA viruses infecting chlorella. Some of the methods employed in their study and that of their hosts are: quantitative PCR, community fingerprinting and targeted sequencing, plaque and MPN assays, photophysiology and respiration measurements, enzyme activity assays, electron microscopy, analytical flow cytometry, and FlowCam imaging.

Current Research Themes in the Nissimov Lab:

1. Effects of environmental change on aquatic viruses    
2. Algal-virus interactions and co-evolution
3. Costs and mechanisms of virus resistance in microalgae       
4. Development of new host-virus model systems

Other ongoing projects in the Nissimov Lab are:

‘The effects of biotic and abiotic stress on microalgal polysaccharide production’

The project aims to identify the type of polysaccharides produced by microalgae in response to biotic (virus) and abiotic (temperature and UV) stress, and the properties of these polysaccharides as it relates to ‘marine snow’ particle aggregation. The project utilizes marine and freshwater algal species and is in collaboration with colleagues in the UK (i.e. Scottish Association for Marine Science).

‘Elucidating algal host-virus dynamics in different nutrient regimes - mechanistic interactions and biogeochemical impact’

This collaborative project aims to bridge existing gaps in the mechanistic and quantitative understanding of viruses as agents of phytoplankton mortality and their impact on biogeochemical processes. Using lab-based experiments with a coccolithophore host-virus model system, as well as extensive datasets from virus-infected natural coccolithophore blooms in the North Atlantic, the project elucidates the impact of nutrient-limitation and host cell fitness on virus infection, and to what degree the dependence of viral infection on nutrient supply impacts large scale biogeochemistry and biogeography of a globally significant phytoplankton species. At the core of the project is characterizing the effects of different nitrogen (N) and phosphorous (P) concentrations on algal-virus interactions and, more specifically, how limitation in either N or P affects the host fitness, its cellular responses to infection, and the virus infection and replication process (e.g. latent period, burst size, virulence). The interdisciplinary approach of this project combines molecular- and flow cytometry-based diagnostic techniques, with the development of mathematical models of infection, to understand the primary mechanisms underlying observed host-virus dynamics. This project is in collaboration with colleagues in the USA (i.e. Rutgers University, University of Tennessee, and MIT).

If you are interested in potential Honours thesis and graduate projects, please contact Dr. Nissimov by email directly (jnissimov@uwaterloo.ca) and include a CV, transcripts, and a brief statement of research interests.

Please see Dr. Nissimov’s Google Scholar profile for a current list of peer-reviewed articles
(https://scholar.google.bg/citations?user=gdwUR1YAAAAJ&hl=en).

• Research Incentive Grant from The Carnegie Trust for the Universities of Scotland (2019)
• Postdoctoral Fellowship at the Institute of Earth, Ocean and Atmospheric Science; Rutgers University (2013-2015) 
• Collaborative Gearing Scheme Fellowship by the British Antarctic Survey (2010-2011)
• UK Natural Environmental Research Council (NERC) Bimolecular Analysis Facility award (2011)
• NERC PhD scholarship (2009-2013)
• MRes tuition fee scholarship from the University of Plymouth in the UK (2008-2009)

Journal Editorship

• Review Editor for Frontiers in Microbiology and Frontiers in Marine Science.
• Editorial Board Member for Viruses (MDPI)

Professional Society Membership

• British Phycological Society (BPS)
• The International Society for Viruses of Microorganisms (ISVM).
• Canadian Society for Virology

Reviewer

Reviewer for PNAS, PlosOne, Environmental Microbiology, FEMS Microbiology, Research in Microbiology, Journal of Plankton Research, Viruses, Virologica Sinica, Virus Genes, Genes, Deep Sea Research Part I (ad hoc), ISME.

• Interdisciplinary Centre on Climate Change (IC3)
• Waterloo Centre for Microbial Research
• Water Institute

2019–2020 Lecturer and a PI at the Scottish Association for Marine Science (UK).

2014–2015 Visiting Scientist at the Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution (USA).

2013–2018 Postdoctoral Research Associate at the Department of Marine and Coastal Sciences, Rutgers University (USA).

2013 Research Assistant at the Department of Plant Sciences, University of Oxford (UK).

2009–2013 PhD Biosciences, Plymouth Marine Laboratory & University of Nottingham (UK).

2008–2009 MRes Marine Biology, University of Plymouth (UK)

2005–2008 BSc (Hons) Marine Biology, University of Plymouth (UK).