Research Projects

1. Microplastics as vectors for pathogen contamination of marine foods –  Plastics are ubiquitous pollutants of marine environments.  Of greatest concern are microplastics (MP), which are particles < 5 mm, that can be ingested by marine organisms and are abundant within aquatic food webs,   Given that microbial biofilms are found on ocean-derived MP, we speculate that pathogen transfer from MP to ingesting aquatic organisms may occur.  Our lab is examining the role of MP in mediating pathogen entry and retention in important marine organisms used for human consumption  by using finfish and bivalve shellfish models. This project is supported by an award from the Maine Sea Grant program.

Generation of bacterial-coated plastic microfibers (MF).  Red fluorescent polyethylene terapthalate (PETP) MF are generated in the laboratory and coated with GFP-expressing bacteria.  (Left to right: Lyle Massoia spooling PETP thread and cutting 50 um PETP fibers on a cryostat, red-fluorescent PETP fibers with a coating of GFP-E. coli.
We use zebrafish as a model to study the effect of microplastics on bacterial entry and retention in edible finfish. The zebrafish work was Lyle Massoia’s MS project, and she was helped by numerous undergrads, including Lauren Adams (pictured at the computer assessing fish gut morphology).
We are also studying the role of microplastics in bacterial colonization of oysters. Burkholder lab MS student, Abigail Blouch-Vigue, is tackling this for her MS project. She partners with Mikayla Straube, MS student of the Byron lab in UNE’s Marine Science program. Mikayla is studying whether rearing oysters in plastic-free aquaculture gear can reduce plastic load in the bivalve’s tissues.

2. Polyphenol-mediated Inhibition of Staphylococcal biofilm formation – The majority of bacterial infections are caused by biofilm-forming microbes.  Since biofilms contribute to virulence, disease persistence and drug resistance, there is urgent need for anti-infection strategies directed at biofilm-forming pathogens.  Our work examines the mechanisms by which polyphenolic compounds, commonly derived from terrestrial and marine natural sources, to impair biofilm formation by Staphylococcus epidermidis and Staphylococcus aureus, two leading causes of biofilm-associated nosocomial infections.  

3. Food safety of edible seaweed – The production and harvest of edible seaweed is the fastest-growing sector of the Maine aquaculture industry.  However, since seaweed aquaculture is a relatively new industry in the U.S, there are no current guidelines for how seaweed should be handled and processed to minimize potential food safety risk.  The Burkholder lab is collaborating with the Byron lab [KB1] in the UNE School of Marine and Environmental Programs to study the effect of post-harvest storage temperature and drying method on viability of bacterial pathogens associated with edible seaweed such as sugar kelp.  This project is supported by an award from the Maine SeaGrant.

Seaweed Food Safety