Abstract
Adaptive laboratory evolution for microbial cells has become an indispensable tool for metabolic engineering and system and synthetic biology. Commercial bioreactors, however, are cumbersome to use and difficult to meet special needs for adaptive laboratory evolution, and there has been the recent renaissance of mini-bioreactor of working volume in the milliliter range. Leveraging on availability of low-cost electronic components such as light-emitting diode and microcontroller board, we have developed a low-cost, flexible, and robust bioreactor platform. We detail two examples of our design, namely the morbidostat and optogenetic bioreactors for antibiotic drug resistance study and optically controlled evolution, respectively. These mini-bioreactors will be useful tools for adaptive laboratory evolution for microbial cells.