While students eagerly await the 4th of July celebrations, why not ignite their scientific curiosity with a fascinating exploration of the microscopic world? Believe it or not, the colors of the American flag can be found in the microscopic world of microbes!
Imagine showing your students a red bacterium that turns white depending on the temperature, a white fungus that adds fizz to a favorite snack, or a blue soil microbe responsible for the earthy scent and creation of antibiotics! This isn’t science fiction, it’s the hidden world of microbes waiting to be explored!
Many of these microbes play important roles in our lives, some beneficial and some potentially harmful. By understanding these tiny organisms, we gain a greater appreciation for the world around us.
That’s where this resource comes in! We’ll delve into the fascinating realm of 4th of July science, exploring three incredible microbes: the red Serratia marcescens, the white Geotrichum candidum, and the blue Streptomyces coelicolor. Your students will learn about their unique properties, their surprising impacts on our world, and the science behind their vibrant colors. Get ready to transform your classroom into a mini microbiology lab and celebrate science this 4th of July!
Red – Serratia marcescens
The bacterium Serratia marcescens produces a bright red pigment called prodigiosin, depending on the temperature it is grown at. It is red at room temperature and white at body temperature. You can find this microbe in your everyday life growing in your bathroom. Have you ever seen that pink stuff on your shower curtain or in your toilet? Meet Serratia marcescens. But clean that stuff up, because it can cause infection.
Serratia actually holds a special place in my heart because it helped save one of my graduate school interviews. Usually, these interviews are relatively painless because the professors happily tell you about their research, and, in return, you share your own research experience. But I had one very awkward interview where the conversation halted far before the interview was over, and so we just sat there. We both stared at the ground and then at each other. I even made a comment about how we were both wearing the same shoes, but she still didn’t say much. Then, thankfully, I noticed a picture of Serratia on the wall showing a color gradient (red to pink to white), which was really neat. I’d never seen anything like it before. So, I commented about how I had previously worked with it, and that got her talking again. She shared that the picture was of Serratia grown at different temperatures ranging from room temperature (bright red) to body temperature (white). And we were able to fill the rest of the interview time discussing it. Serratia helped me turn an awkward situation to a less awkward one, and thus it is special to me.
The photos below were taken by Tasha Sturm, who regularly shares incredible photos of microbes on her Twitter and Instagram accounts.
White – Geotrichum candidum
The fungus Geotrichum candidum can be found in many different environments, including raw milk, soil, plants, and even mammals. This versatile microbe forms beautiful white velvety colonies. What makes it delightful, though, is that it helps mature cheeses and is part of the starter culture for the Finnish fermented milk product viili. Geotrichum candidum can also produce carbon dioxide in viili if it is in a sealed container, making this food fizzy.
I ran across this microbe on Instagram through Olga Pinegina’s account in_petri when she posted some beautiful photos of it. So, I contacted her, and she was kind enough to let me post a couple of them here.
Blue – Streptomyces coelicolor
During graduate school, I taught a microbiology lab for the Freshman Research Initiative (FRI) Antibiotics Discovery stream. This program is highly beneficial for the students because they have their own research projects. The goal of the Antibiotics Discovery stream was to isolate soil-dwelling Streptomyces species because they are well-known for their ability to produce antibiotics. Although many antibiotics have been discovered and are used clinically, some are not as effective as they used to be because of increasing antibiotic resistance in bacteria. So, to isolate microbes from the soil in hopes to discover novel antibiotics, we walked around the University of Texas at Austin campus and took soil samples from any location the students got excited about. I also took a sample of my own from cactus soil, because, have I mentioned my obsession with succulents yet?
One of the best parts of working with Streptomyces species is the smells they produce. They and other soil-dwelling microbes are actually responsible for the smell of dirt. So, when you grow them in the lab, they make this wonderful aroma, which you get to enjoy every time you open the incubator to check on them.
One of these organisms, Streptomyces coelicolor, produces a blue pigment actinorhodin, which is also an antibiotic. Dr. Vineetha Zacharia has taken advantage of this beautiful pigment by creating paintings using the actinorhodin as paint. If you are interested, you can commission her to create something for you. You can follow her on Twitter and Instagram.
So there you have it! We’ve explored three fascinating microbes – the red, white, and blue wonders of the microscopic world. This 4th of July, as you celebrate with family and friends, take a moment to appreciate the hidden world of microbes that surrounds us. Remember, these tiny organisms play a crucial role in our lives, from helping develop delicious foods to producing life-saving antibiotics.
For teachers, this post offers a springboard to ignite a love of science in your students. You can easily adapt this to different age groups, sparking curiosity and fostering a deeper understanding of the microscopic world.
So, this 4th of July, celebrate not just our nation’s independence but also the incredible world of science and the tiny wonders that contribute to our lives in surprising ways!
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