# Position-dependent changes in phycobilisome abundance in multicellular cyanobacterial filaments revealed by Raman spectral analysis

## TL;DR

This paper uses Raman microscopy to show how pigment levels in cyanobacteria vary based on cell position in a filament.

## Contribution

The study reveals position-dependent changes in phycobilisome abundance in cyanobacterial filaments using Raman spectral analysis.

## Key findings

- Raman bands for phycocyanin and allophycocyanin are stronger in vegetative cells than in heterocysts.
- Pigment intensity in vegetative cells decreases as they are positioned farther from heterocysts.
- Cell pigment composition is influenced by their location within the filament.

## Abstract

The one-dimensional filamentous cyanobacterium,
Anabaena
sp. PCC 7120, shows a simple morphological pattern consisting of two distinct cell types under nitrogen-deprived conditions. We found that microbial pigment composition in differentiated (heterocyst) and undifferentiated cells (vegetative cells) can be distinguished using Raman microscopy. The Raman bands associated with phycocyanin and allophycocyanin were of higher intensity in vegetative cells than those in heterocysts. However, these bands had statistically lower intensity in vegetative cells located further away from heterocysts. That is, the pigment composition in individual cells is affected by locational information in a filament.