by Britt Flaherty
|Christine Shulse working in Puerto Rico while|
collecting rare microbial samples
Christine is a graduate student in Dr. Eric Allen's lab at The Scripps Institute of Oceanography, and she's discovering a source of PUFAs, a form of secondary lipids, in bacteria: "Generally I'm interested in the production of secondary lipids by microbes," she says. "Similar to secondary metabolites, secondary lipids are lipids that have not been shown to be necessary for the normal growth, development, and reproduction of these microbes under laboratory conditions. Therefore these pathways can hopefully be messed with without upsetting the cell's primary metabolism." This would allow Christine to artificially produce more or less secondary lipids in a microbe without affecting its health, which is important for engineering bugs in industrial settings.
|Christine in the Lab in San Diego|
Christine's work utilizes cutting edge DNA sequencing technology and bioinformatics as well as environmental samples from all over the world, including bacteria from Lake Tyrell in Australia and even samples from 6000 meters below the ocean surface in the Puerto Rico Trench. She hopes to discover and understand energy-containing molecules that are already being made in nature and is searching for these molecules in extreme environments. "I have surveyed various environments for the genetic signatures ultimately responsible for the production of secondary lipids so that we can get an idea of the diversity and distribution of secondary lipid production in nature," she says. She has also scanned every sequenced genome (millions of genes worth of information) from algae to cyanobacteria to protists, looking for genetic signatures of PUFA and hydrocarbon production.
Christine analyzes every gene expressed by microbes that produce secondary lipids through high-throughput transcriptomics, or the study of gene expression in the entire organism. She looks at changes in gene expression when you change the microbe's environment, trying to decipher the triggers of lipid production. "I'm quantifying the trade-off between hydrocarbon and fatty acid production in a group of marine bacteria called Shewanella," she says.
|The view from the boat in Puerto Rico|
This summer, the Allen lab is even hosting an SD-CAB summer undergraduate intern, Michael Mayfield. Michael is working closely with Dr. Allen on a project that compliments Christine's work, scanning new microbes for secondary metabolite production and trying to find strains that make these important molecules.
Christine's work and the work of the Allen group may one day leave the lab in pill or gasoline form, and while it won't make my french fries healthy, it may replace expensive fish oil supplements or help reduce the environmental impact of our energy needs.
Britt Flaherty is Ph.D. candidate at UCSD and a volunteer writer and outreach coordinator with SD-CAB. You can contact her at firstname.lastname@example.org.