Protecting Fish: Identifying Oomycete Growth Inhibitors

Oomycetes are fungus-like eukaryotes that pose a significant threat to freshwater environments as they can infect freshwater animals like crayfish and salmon. Salmon farmers have reported up to 50% of their stock being lossed due to infections by Oomycetes. Conventional methods of controlling such infections often involve using harmful chemicals. One such chemical is a cheap organic dye called malachite green which is currently banned in most states for use in aquaculture due to its toxic effects on human health. As with most things, in our search for a safer and environmentally friendly alternative, we can turn to nature to look for a solution. As it turns out, some bacteria found on freshwater fish and crayfish have the ability to inhibit oomycete growth. Although there is research into what specific strains of bacteria have this ability, how they inhibit Ooymcete growth remains unclear.

In this project, we aim to use simple molecular techniques to try and characterize the substance or substances that cause the inhibition of Oomycete growth. We will learn how to prepare culture media for Oomycetes. We will learn how to isolate bacteria from freshwater samples. We will learn how to prepare culture media for bacteria. We will test different components of bacterial solutions for the ability to inhibit Oomycete growth. We will use a polymerase-chain reaction to isolate and amplify the 16s rRNA from bacteria. We will also use phylogenetic tree construction to try to identify the isolated bacteria.