The Color of Survival - An Inquiry-based Inter-disciplinary Study of Bacterial Pigments

Oct 15, 2026

Uploaded by Mary Man

Pigments are light-absorbing natural substances that shape coloration, camouflage, mate or pollinator attraction, and photosynthesis. Among microbes, pigments occur across many phyla and often support roles beyond photosynthesis. This inquiry-based, interdisciplinary study guides students to evaluate the cost and benefit of heritable pigment production and its survival impact in competitive, hostile environments. It connects physics, chemistry, biology, and art through active small-group learning.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages9

Reading Time23 min

AccessFree to download

Introduction

Pigment production in bacteria

Pigment studies as an inter-disciplinary STEM project

An inquiry-based learning module using pigmented bacteria

Putative functions and examples

The Color of Survival: An Inquiry-based Inter-disciplinary Study of Bacterial Pigments José de Ondarza, Ph.D. Department of Biological Sciences, SUNY Plattsburgh, Plattsburgh NY 12901 [deondarza@plattsburgh.edu](deondarza@plattsburgh.edu) Abstract. 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. Keywords: Interdisciplinary; inquiry-based; bacterial pigments; microbiology; physics Introduction Pigment production in bacteria. If you have ever had the opportunity to grow bacteria in a classroom, you will likely have noticed that these microbes can be surprisingly colorful. I am fascinated by the colors produced by bacteria, both in teaching undergraduate microbiology and through my own research. Many bacteria have the ability to produce pigmentation, spanning the spectrum of color from dark purple to yellow. Pigments include violacein (purple), prodigiosin (red), carotenoids (orange-yellow), fluorescein (greenish-yellow), and pyocyanin (bluegreen) . Colorful bacteria can be isolated from many common sources, including soil, water and human skin. The frequency with which such pigmented bacteria can be isolated from environmental samples suggests that pigments must play an important role, since each pigment requires enzymatic pathways to synthesize them that can be quite complex and therefore costly. The production of prodigiosin by Serratia marcescens, for instance, requires more than a dozen different enzymes (Harris et al., 2004)! Have you ever wondered what function these pigments really play? The following is an inquiry-based approach to studying pigments that can be used in diverse settings, including non-majors biology, ecology, chemistry, and physics courses as well as general microbiology classes. The above-mentioned question is an excellent starting point for having students think about science at multiple levels, including structure – function relationships, heritability and expression of biological traits, natural selection and the cost/benefit of pigment production, physical and chemical properties of pigments, and so on. Pigment studies as an inter-disciplinary STEM project. Although the most obvious questions about bacterial pigments relate to their biological role, don’t miss the opportunity to delve into inter-disciplinary ideas! Pigments are often quite complex chemical compounds composed of one or more cyclic hydrocarbon skeletons. The spectrum of light that is absorbed by a pigment (a.k.a. its absorption spectrum), and hence its color, depends on the chemical structure of the pigment, and changes to this structure can change the color. Use this pigment study to integrate concepts of organic chemistry and physics of light into your class. Likewise, the calculations of dilutions and bacterial numbers integrate math skills. An inquiry-based learning module using pigmented bacteria Do bacterial pigments have a purpose beyond the merely decorative? Your students are sure to have some good ideas. An open-ended group discussion is going to produce a variety of possible answers, many of which are testable in

FAQs

What roles do bacterial pigments potentially serve besides coloration?

The text presents multiple testable purposes, including antibiotic properties, UV/light protection, competition or predation protection, and antioxidant roles. It also notes photosynthesis-related functions for some microbial groups, especially algae and certain bacteria.

How does the study frame pigment production as a learning activity?

It uses an inquiry-based approach where students consider the cost and benefit of a heritable trait (pigment production) and how it affects survival under competitive and hostile conditions. Discussion and hands-on activities are designed to support multi-level thinking.

Why are bacterial pigments useful for interdisciplinary STEM learning?

The document links chemical structure to absorption spectra and color, enabling integration of organic chemistry and physics of light. It also ties dilution and bacterial count calculations to math skills, supporting broader cross-disciplinary learning.

Oct 15, 2026

Uploaded by Mary Man