Plastic bag bioreactors are single-use bioreactors, frequently used in solid culture fermentation. This study developed plastic bag bioreactors with more effective aeration conditions and particular connection elements that yield sensors, environmental control, and modular connectivity. This bioreactor system integrates the bags in a chain that circulates air and moisture through filtered connections. Within the present scope, this study also aimed to reveal that cultures in different plastic bags can be produced without affecting each other. In this direction, biomass production in the modular chain bioreactor (MCB) system developed in this study was compared to traditional bag systems. In addition, contamination experiments were carried out between the bags in the system, and it was observed that the filters in the developed system did not affect the microorganisms in different bags.