Maple sugaring is the process of collecting sap from maple trees in the early spring and then boiling the sap to make maple syrup.
Microbes such as bacteria and yeasts can grow in the maple sap. The extensive boiling process kills the microbes so that they are no longer present in the final maple syrup. However, the microbes can still influence the color and flavor of the syrup by altering the chemical makeup of the sap. Maple sugar makers know that their syrup will change color and flavor (also known as the grade of the maple syrup), depending on factors such as the outside temperature and how late in the sugaring season the sap is collected. Much of this effect is thought to be due to the microbes, since they can grow more quickly in warmer temperatures.
Microbial communities surround us. These communities can consist of many species of microbes or just a few. They exist in almost every imaginable place, ranging from a simple community of bacteria in your yogurt to a complex community inside the human gastrointestinal tract. Microbes also exist in the ocean, in the soil, on plants, in other animals, and many, many other places. These microbes shape our world and impact our health, technology, and food. Therefore, it is important to understand how these microbe communities are formed and what factors shape these communities.
The microbes that grow in sap offer an example of a simple microbial community that we can study in order to gain a better understanding of microbial communities overall. Moreover, these microbes have a practical application, because the microbes can change the composition of the sap and therefore affect the maple syrup. This can be positive, such as creating the spectrum of desirable color and flavor profiles in the different grades of maple syrup, or it can be negative, such as when sap becomes overgrown by microbes and cannot be used to make high-quality syrup.
Finally, the study of microbial communities in maple sap offers an example of a microbial community that is interesting for all levels of work and education. From scientific collaborations with sugar makers to educational activities for children, this work offers an exciting point to begin the conversation about how microbes influence our world and how we can study these microbes.