Microbial Art Project: Science You Can Eat!

Positively-Delicious & No-Negativity Here White Chocolate Cheesecake

Cristina Mondelli


For the longest time I had the hardest time remembering the difference between gram-positive and gram-negative staining. Fortunately, designing a dessert around these two types of bacteria made studying much more fun! Gram-staining is a critical part of characterizing an unknown bacterial species. Gram-negative bacteria turn pink/red under the microscope after staining while gram-positive bacteria turn purple. The crystal violet stain included in gram-staining gives the peptidoglycan layer its purple color in gram-positive bacteria. The thick peptidoglycan layer is modeled in the dessert by the thick white chocolate cheesecake layer. The gram-positive cheesecake is covered in a dark purple blackberry topping to represent the way the cells look under a microscope. The gram-negative cheesecake has several layers representing the various layers of the cell membrane. The bottom crust is the plasma membrane and the red strawberry layer is the periplasmic membrane. The cheesecake also represents the peptidoglycan layer in the gram-negative bacteria. Red strawberries were chosen because the color matches gram-negative bacteria.