The Color of Survival: An Inquiry-Based Inter-Disciplinary Study of Bacterial Pigments

Pigments are light-absorbing substances that are abundant in nature, serving roles in coloration, camouflage, mate/pollinator attraction and photosynthesis among higher life forms. Among microbial organisms, pigments can also be found in a wide range of phyla. While some of these pigments function in photosynthesis, namely among algae and some bacteria, the great majority of microbial pigments play entirely different roles. The exploratory study presented here will stimulate students to think about the cost and benefit of a heritable trait (pigment production) of microscopic organisms and its effects on survival in a competitive and hostile environment. Exploring and understanding the roles these pigments play allows for a number of cross-disciplinary learning opportunities that combine physics, chemistry, biology and even art, and can be set up as an inquiry-based learning module suitable for small-group and active learning experiences.