MSc. Paul-Adrian Bulzu, Ph.D.

My research focuses on virus-protist interactions and microbial ecology in freshwater ecosystems. Using cultivation together with genome-resolved sequencing approaches, I investigate how viruses shape the ecology and evolution of microbial eukaryotes. In particular, my work explores giant viruses of the phylum Nucleocytoviricota that infect unicellular algae and polinton-like viruses (PLVs), a group of viral elements that may function as antiviral defence systems within eukaryotic hosts.

Freshwater ecosystems provide excellent model systems for studying microbial diversity and virus-host interactions. Although lakes and reservoirs harbour immense microbial and viral diversity, many of their inhabitants remain poorly characterised. Advances in sequencing technologies now allow us to access this hidden diversity directly from environmental samples and to reconstruct genomes of both microbes and viruses without the need for cultivation. By integrating long-read sequencing, metagenomics, and metaviromics with laboratory cultivation, we aim to link environmental viral genomes to their hosts and to understand how virus-host interactions influence microbial community dynamics. A central aspect of this work is the study of virus-virus interactions, particularly those involving giant viruses and their viral parasites (virophages and polinton-like viruses). Combining environmental sequencing with experimentally tractable systems, we investigate how these interactions influence viral evolution, host genome architecture, and the dynamics of freshwater plankton communities.

My previous work in this field was centered around the identification and characterization of large collections of polinton-like viruses integrated within protist genomes. Current research continues to explore how these viral elements shape protist genome evolution and influence ecological processes during seasonal algal blooms.