Evolution, detrimental effects, and removal of oxygen in microalga cultures: A review

Large quantity of oxygen evolves as a byproduct of photosynthesis in microalga cultivation. As a result, dissolved oxygen of 100–400% air saturation or even higher is commonly observed in microalgal cultures. High concentration of dissolved oxygen may inhibit photosynthesis, cause photochemical damages to photosynthetic apparatus and other cellular components, result in reduction of cell growth or even culture collapse. Effective deoxygenation mechanisms are required to maintain dissolved oxygen at a level that is not inhibitory. This remains a significant challenge despite of the enormous technical advances in this field and information on large scale photobioreactors are scarce, which warrants systematic future studies, especially with controlled large‐scale systems, in this important field.