About This Project

I want to document the species of microbes (microbiome) in sourdough starters, and quantify how they change depending on the nutrients they are given to grow. I intent to grow culture with nutrients such as: white flour, rye flour, potato starch, sucrose, honey, and high fructose corn syrup; and then monitor any changes to the microbial community in the sourdough starters.

Ask the Scientists

What is the context of this research?

Sourdough bread is a fermented food that is made from a sourdough starter culture. The starter culture contains a symbiotic mixture of bacterial and fungal microbes, an ecosystems that provide ample opportunities to identify processes that structure microbiomes. The main microbes responsible for fermentation in sourdough cultures are yeasts, lactic acid bacteria, and acetic acid bacteria. Together these microbes shape the texture, taste, nutrition, and stability of the finalized food product (1,2,3,4,5). Only recent research has looked at the diversity of these sourdough cultures at a species level (6,7,8).

What is the significance of this project?

This project will provide novel data pertaining to the impacts of nutrient sources on the microbial populations in a sourdough culture. This has specific impacts on the food industry, in understanding how the preparation of microbial colonies can impact an end food product's nutrition and quality. The work will also provide data relevent to human health, as a simple model of how a microbiome (such as the gut microbiome) could change when exposed to diverse nutrient sources. The project is ultimatly being designed to implement in an undergraduate reseaseach experience and will create access hands on lab training at a minorty serving institution (University of the District of Columbia).

What are the goals of the project?

Starting this summer (June 2021), undergraduate students will set up fifty sourdough starter cultures to grow under standardized environmental conditions. Each culture will be started from one "mother" culture - thus all having an identical set of starting microbes. Each starter will then be feed using a different nutrient source. Sources will include: white flour, rye flour, potato starch, high fructose corn syrup, honey, and sucrose. Additional nutrient sources will be chosen by the student researchers. After growth on the unique source for two months, all cultures will be extracted and analyzed using metagenomics. We will use 16S and ITS metagenomic analyses to identify the types of bacterial microbes, and eukaryotic microbes (respectively) in each culture system.