The influence of protozoa with a filtered and non-filtered seawater culture of Tetraselmis sp., and effects to the bacterial and algal communities over 10 days

In this study a filter was used to remove protozoa and its effects on a Tetraselmis sp. culture were evaluated in terms of final total lipid, final total dry weight, cell counts, and both the bacterial and algal communities. The protozoa species observed within this study was identified as Cohnilembus reniformis. It was observed that on the final day no C. reniformis were present in filtered cultures compared to the non-filtered culture which contained 40 ± 3 C. reniformis/mL. The presence of C. reniformis within the culture did not affect the total lipid or the total dry weight recovered, suggesting that Tetraselmis sp. was capable of surviving and growing in the presence of C. reniformis. Overall it is suggested that an 11 μm filter was effective at removing protozoa, though growing a microalgae culture without filtration did not show any significant effect.