A casual observer passing by Youngchild 257 during Spring Term might be forgiven for thinking that Lawrence has added home economics to its traditional liberal arts curriculum. As the pungent smell of sauerkraut mixes with a whiff of yeast and freshly made sourdough bread, one can not help but notice that this biology laboratory is a bit unusual. Welcome to Bill Perreault's BIOL 26: Principles and Applications of Microbiology.
BIOL 26 is the study of bacteria, viruses, fungi, and algae--their physiology and the adaptations that allow them to exploit certain environments. Throughout the term, students are introduced to the names and habits of microorganisms. Beginning in the fourth week, they learn something else as well--how bacteria and molds are not only naturally present in many of the foods we eat but crucial to their creation.
Professor Perreault began introducing experiments in food production into his microbiology course in 1986, starting with the chemical processes of making yogurt and fermenting wine and adding other foods over the years, until BIOL 26 became known as the Food Lab.
"Microbiology can be a grave subject," says Perreault. "It often deals with organisms that cause human misery." Most college courses in the subject, including BIOL 26, stress the medical aspects of microbiology, but Perreault began to believe something was missing. "People don't understand what benefits we get from these critters." He introduced the Food Lab component to provide more balance and expose his students to another facet of the human-microorganism relationship.
Intermixed with experiments on bacterial cultures from river water and other assorted vials and beakers, labels on the shelves of one of the incubation chambers in Youngchild 257 read "Chateau Perreault," "La Casa Del Queso," and ""Krautmachen Gehausen"--the gestation center for the Food Lab. Over in a corner of the blackboard, the ingredients for yogurt are clearly spelled out: Lactobacillus bulgaricus and Streptococcus thermophilis. A note adds that "If you want to disgust your friends, 1) spread, 2) heat fix, 3) rinse with Xylol, and 4) stain with methylene blue." The latter reflects Perreault's point that the Food Lab is "fun but not frivolous." The method identified allows students to see the presence of bacteria in the yogurt, by applying a laboratory technique they have been trained to use in general microbiology.
To enrich the students' understanding of microorganisms in food, Perreault regularly offers up a bit of folklore. In explaining why sauerkraut and yogurt came into being, he provides an anthropology lesson on how sauerkraut was an inexpensive invention that allowed northern European peasants to survive harsh winters and yogurt was a clever means for nomadic peoples to store and move dairy products.
The final day of class in BIOL 26 is both a culinary celebration and a self-administered final exam, as the results of the experiments are unveiled. The menu is quite impressive, in addition to the sauerkraut and sourdough bread, there are fresh cheese curds, yogurt, and a wide choice of red and white wines. Perreault, the wine taster for the group, pronounces on the success of each students' endeavor, grimacing only occasionally at a less than satisfactory result. As he makes the rounds of the experiments, he carefully points out the two stages of post-fermentation in winemaking. Decanting the wine--that is, pouring out the product from the top and leaving the yeast-cultivated residue behind-- prepares the wine for aging. Organic acids do the rest, providing the extra chemical step that gives a really good wine its important character. As if to remind students of their presence in a scientific laboratory, a notice on the blackboard instructs "microbes" (the students' nickname for themselves) to "check all incubators for old, unwanted cultures -- Out They Go!"
Students in BIOL 26 agree that the Food Lab is a fun way to learn science but are quick to point out that this is serious business indeed.
"We went over numerous practical and medical applications of microbiology, such as new methods of gene splicing and the role plasmids play in creating resistance to antibiotics," says Eric Bohmer, '00. "After learning the theory and the science of microorganisms, the Food Lab gave us an opportunity to see it all in action." Bohmer adds that what looks like simple food preparation is, in fact, a lab practicum that involves detailed work in identifying strains of bacteria and fungi and applying the techniques for culturing them.
Summing up the value of the Food Lab experience, a small group of BIOL 26 "microbes" readily agreed with a classmate's off-hand observation -- "It certainly makes you think more about what you are eating."
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