Answer: It would kill the anaerobes.
Explanation:
Cyanobacteria are the group of bacteria that can perform the process of photosynthesis. These bacteria are able to sustain their life on their own.These bacteria release oxygen into the environment in which they are living.
Anaerobes are group of bacteria that thrive in the absence of oxygen. If these bacteria are provided with oxygen released by the cyanobacteria will kill anaerobes.