Related Experiment Video
Updated: Jun 27, 2025
Spectrophotometric Determination of Phycobiliprotein Content in Cyanobacterium Synechocystis
Published on: September 11, 2018
Potential gap in understanding cyanoHABs: Light-dependent morphological variations in colonial cyanobacterium
Ganyu Feng1, Jun Cao2, Huaimin Chen3
1Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China; College of Environment, Hohai University, 1 Xikang Road, Nanjing, Jiangsu 210098, China; Shanghai Institute of Pollution Control and Ecological Security, 1239 Siping Road, Shanghai 200092, China.
Microcystis colonies grow larger in sufficient light but become less dense and develop pores under light limitation. This adaptation helps cyanobacteria avoid self-shading, impacting harmful algal bloom dynamics.
Area of Science:
- Environmental Microbiology
- Phycology
- Algology
Background:
- Colony formation is key in Microcystis, a cyanobacterium causing harmful algal blooms (cyanoHABs).
- Larger Microcystis colonies often show decreased density and light penetration.
- Intra-colony self-shading (ICSS) is a known factor affecting cyanobacterial growth.
Purpose of the Study:
- To investigate how light limitation influences Microcystis morphology.
- To understand the relationship between light, colony size, and cellular arrangement.
- To explore Microcystis' adaptation strategies to crowded cellular environments.
Main Methods:
- Culturing Microcystis under varying light conditions (100% to 1% transmittance).
- Measuring colony size and observing cellular arrangement.
- Analyzing growth rates and cell division frequencies.
Main Results:
- Sufficient light (100% transmittance) significantly increased colony size (466±15 μm to 1030±111 μm) with a growth rate of 0.11±0.01 day⁻¹.
- Light limitation (50%–1% transmittance) resulted in no significant colony size increase and a negative growth rate.
- Light-limited Microcystis displayed loose cell arrangements and internal pores, confirming a negative correlation between colony size and cell packing.
Conclusions:
- Microcystis adjusts colony structure, developing looser arrangements and pores, to mitigate intra-colony self-shading under light limitation.
- This morphological plasticity is a critical adaptation for Microcystis survival and has implications for predicting and managing cyanoHABs.
- Findings enhance understanding of cyanobacterial adaptations and phycosphere interactions.
