Matters Microbial #58: Exploring Bacterial Viruses from Coral Reefs to Other Planets with Dr. Cynthia Silveira
0:25 Introduction: Dr. Cynthia Silveira, a marine biologist and virologist at the University of Miami, joins the podcast to discuss her work on bacteriophages.
4:21 Dr. Silveira's Journey: Dr. Silveira shares her background in marine biology, her introduction to bacteriophages during her PhD, and the influence of the Forest Rohwer lab at San Diego State University on her research.
10:20 Bacteriophages in Coral Reefs: Dr. Silveira explains the critical role of bacteriophages in coral reef ecosystems, emphasizing their impact on bacterial abundance and coral health. She notes that in degraded reefs with high bacterial loads, phages tend to shift from lytic (bacteria-killing) infections to lysogenic (genome-integrating) infections, potentially leading to increased bacterial pathogenicity.
17:34 Viral Dark Matter: The discussion highlights the vast unknown in the viral world, with over 90% of viral genome sequences lacking functional annotation. Dr. Silveira describes the use of epifluorescence microscopy to visualize and count viruses in seawater samples.
28:49 Meromictic Lakes and Astrobiology: Dr. Silveira introduces her NASA-funded research on meromictic lakes, which serve as models for ancient Earth oceans and potentially for extraterrestrial environments. The research focuses on how viral infections of phototrophic bacteria in these lakes can influence biosignatures (chemical traces of life), with implications for understanding past life on Earth and the search for life on other planets.
39:23 Viral Impact on Gene Diversification: Dr. Silveira discusses how viruses contribute to the diversification of genes in microbial communities through horizontal gene transfer and potentially accelerated adaptation processes.
42:00 Biology of Viruses Course: Dr. Silveira describes a unique project-based course she teaches where students analyze unidentified viral genomes using bioinformatics tools. This approach allows students to develop independent research projects based on their interests and explore diverse aspects of virology.
50:38 Inspiration to Become a Microbiologist: Dr. Silveira recounts a pivotal experience in a virology course during high school, where exposure to research labs and the diversity of viruses sparked her passion for microbiology.