A reactor system includes a support housing having an interior surface bounding a chamber, the chamber having a vertically extending central longitudinal axis. A flexible bag is disposed within the chamber of the support housing and has an interior surface bounding a compartment. A mixing element is disposed within the compartment of the flexible bag. A drive element, such as a drive shaft, is secured the mixing element, wherein the mixing element is laterally offset from and/or is angled relative to the vertically extending central longitudinal axis of the support housing.