What pigment is responsible for the blue color in cyanobacteria?

The blue color in cyanobacteria is primarily due to the pigment phycocyanin. This pigment is a type of accessory pigment that plays a critical role in the photosynthetic process. Phycocyanin absorbs light in the orange and red wavelengths, which allows cyanobacteria to effectively capture energy from sunlight, particularly in aquatic environments where light conditions can vary.

In addition to its role in photosynthesis, phycocyanin serves other functions, such as protecting the cells from oxidative stress and contributing to the characteristic coloration of these organisms, which can be visually striking in various water bodies. Therefore, the presence of phycocyanin is essential not only for the distinctive blue coloration of cyanobacteria but also for their survival and ecological functions within their environment.