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Construction and Operation of an Affordable Laboratory Photobioreactor System for Simultaneous Cultivation of up to 12 Independent 1 L Cyanobacterial Cultures

A large field of research has developed for the study of cyanobacteria for photosynthetic chemical production. Understanding the bioenergetics of growth and product secretion of cyanobacteria requires experiments in controlled environments with volumes large enough to allow sampling over time without removing most of the culture medium. The cost of commercial laboratory photobioreactors makes these experiments inaccessible to many researchers and limits experimental throughput. In this work, we designed and constructed a system of 12 independent, sterilizable cyanobacterial photobioreactors for cultures up to 1 L in volume for a cost less than a single commercial photobioreactor. This system allows gas mixing to a desired CO2 concentration for transfer to the culture medium, discrete modulation of light intensity through addition/removal of fluorescent tubes, temperature control in the range of ambient temperature to 45 C, and simple sterile sampling for monitoring throughout long-term growth experiments. In the following sections, we will describe the assembly and operation of this photobioreactor system.