Effect of Different Shaking Systems on the Growth of Marine Diatom Phaeodactylum Tricornutum

In aquatic ecosystems, the fact of encountering fluctuations is vital for the survival of phytoplankton, in terms of remaining in the euphotic zone and reaching the necessary nutrients for their growth. The existence and the abundance of the phytoplankton are also vital for the other living things in indirect or direct ways, due to being the fundamental components of the food chain and webs, in addition to their usage in several industries like fuel, pharmacy, or cosmetics. However, particularly for the energy industry, the production cost of biofuels by using phytoplankton is relatively higher than the cost of conventional fossil fuels. Thus, the need of increasing the phytoplankton biomass in artificial environments has emerged to reduce the biofuel production cost. For this purpose, the correlation of turbulence and growth rate has been investigated through various experimental studies. In addition to the previous studies, this study focuses on the turbulence effects at a small scale in respect of the movement directions. Fixed, axial, and orbital movements were performed and quantified in terms of the specific growth rate, doubling time and the productivity of biomass for each system. The frequencies of the axial and orbital systems were set to 40 and 80 rpm, respectively and the specific growth rates were quantified as 0.38, 0.43 and 0.42 μ day-1 whereas the doubling times were calculated as 1.84, 1.62 and 1.63 day. In conclusion, it was observed that the frequency of the movement is more influential rather than the type of the movement.