Microorganisms and typical organic matter responsible for lacustrine “black bloom”

- Sulphate-reducing bacteria were the motor of the lacustrine black bloom occurrence.
- The sulphur in protein was the key factor to lacustrine black bloom formation.
- The abrupt increase in H2S signalled the impending formation of black bloom.

Identifying the causation of the black substance in lacustrine “black bloom” is of great significance for forecasting and preventing black bloom in many waters of the world. In this research, an array of black bloom was simulated in a laboratory to investigate how microorganisms and organic matter affect black bloom. Sulphate-reducing bacteria (SRB) are the main biological factor, and protein is the key organic factor contributing to lacustrine black bloom. The black colour of black bloom is strongly associated with a relatively high SRB population density. Hydrogen sulphide concentration can serve as a predictor of black bloom.