High throughput is essential for identifying optimal process conditions or screening for new production strains. This has given rise to the development of microbioreactor (MBR) systems following the rules of miniaturization, parallelization, and automation [34; 35]. MBRs can be either scaled-down stirred-tank bioreactors [36; 37] or shaken bioreactors [38; 39]. For automated and unsupervised operations, these MBRs are commonly placed inside a liquid handling station (LHS). Besides various prokaryotic microorganisms [40; 41; 42], yeasts such as _Komagatella pastoris_ have also been cultivated in miniaturized stirred-tank bioreactors, whereby scalability was demonstrated up to the m\({}^{3}\) scale [43]. For cell cultures, MBR systems are designed with significantly lower shear forces [44]. For small-scale stirred-tank bioreactors, different stirrers have been designed for different energy dissipation and gas exchange values [36; 41; 45]. Recent developments focus on new sensors [46] and the smart integration of multiple laboratory devices [47]. The concept of MBRs is to be transferred from heterotrophic to photoautotrophic cultivation. Some of the aforementioned items associated with miniaturization, such as low-volume flat plate PBRs [48] or parallelization in MTPs [20] have already been realized. To the best of our knowledge, miniaturized stirred-tank PBRs have, however, not yet been described. Light with a wavelength of between 400 and 700 nm is defined as photosynthetically active radiation (PAR) [49; 50]. Within the PAR range, light is absorbed at various efficiencies by the chlorophyll in microalgae and the associated pigments. Some studies have analyzed algal growth using only red and/or blue light [51; 52; 53; 54]. However, sunlight will probably continue to be the primary energy source for economically feasible production processes. For this reason, white light with a broad spectrum is preferred with laboratory-scale PBRswhen scale-up is desired. This is why the use of light-emitting diodes (LEDs) is gaining relevance in the cultivation of microalgae for research and development. They are long-lasting, have a defined emission spectrum, and are electronically dimmable. LEDs can be dimmed either by constant current reduction (CCR, analog dimming) or pulse-width modulation (PWM, digital dimming). Such characteristics as small size and low radiant energy dissipation [55] are ideal for miniaturized PBRs due to the general space limitations and, especially, to the need for cooling. When it comes to controlling such constant current sources, microcontrollers are an excellent solution. The required components can be stacked on a single chip (a so-called \"system on a chip\") [56]. The software is loaded into the read-only memory (ROM), which generates the output values. Furthermore, input signals, which control the script and output values, can be received via sensors. Parallelized, miniaturized, and automated PBRs would be beneficial for efficient microalgae screening, media optimization, and bioprocess development, but, unfortunately, these are not yet in sight. An established MBR system that employs single-use stirred-tank bioreactors and can be operated with an LHS is to be adapted for photoautotrophic cultivation. In this context, new LED illumination modules are to be constructed, which are adapted to the MBRs using a controller unit for standalone use. The new parallel PBRs are to be evaluated based on examples of automated photoautotrophic batch cultivations of _Microchloropsis salina_ using either varying constant incident light intensities or dynamic day and night cycles.