Award: OCE-1756851

Cable bacteria (Electrothrix spp. and Electronema spp.) are notable for performing sulfur oxidation through transmission of electrons from sulfide in anoxic sediments to oxygen in surface sediments as well as their world-wide distribution. Through this movement of electrons cable bacteria cause notable impacts to the sediment environment, including changes to pH, sulfur, and iron chemistry. These chemical factors have been shown in other studies to be important controls of bacterial community structure and function. In this study we investigated how cable bacteria impact other microorganisms in the sediments in which they are active. In one study, we used publicly available DNA sequencing data to learn which bacteria live along side bacteria. Using public data allowed us to study cable bacteria sites from fresh and saltwaters around the world. We observed that cable bacteria consistently live alongside specific sulfur oxidizing and sulfate reducing bacterial species. Our results agreed with directed site-specific studies, suggesting the types of bacteria that live with cable bacteria in well-studied environments hold true globally. Through experiments in which we manipulated the growth and activity of cable bacteria we used with DNA and RNA sequencing techniques to study the activity of microbes in sediments in which cable bacteria can live. Our results suggest that cable bacteria impact other microbes in the sediments in a variety of ways that appear to differ with sediment depth. In the surface sediments evidence suggested that the presence of cable bacteria was associated with predatory bacteria while they appeared to suppress the abundance of certain types of carbon fixing bacteria. Deeper in the sediments multiple types of bacteria responded positively to cable bacteria, including magnetotactic and sulfur oxidizing bacteria. Last Modified: 10/28/2023 Submitted by: Matthew Saxton