While the study provides robust evidence linking oxidative stress to reduced pertactin productivity, the conclusions heavily rely on controlled bioreactor conditions and specific glutamate-induced stress scenarios. However, the generalizability of these findings to industrial-scale fermentation, where additional stressors such as shear forces, nutrient gradients, and contaminant risks exist, remains unclear. Could the authors clarify how these factors might influence oxidative stress dynamics and productivity? Furthermore, the relationship between glutamate levels and ROS appears linear within the tested range—were broader glutamate concentrations or alternate carbon sources examined to explore potential non-linear effects?
The study demonstrates a clear link between oxidative stress and pertactin yield, however, it does not delve into the potential role of specific oxidative defense mechanisms employed by B. pertussis. For example, enzymes like catalase or superoxide dismutase may play critical roles in mitigating ROS effects. Were these or other oxidative stress response pathways analyzed to understand their contribution to maintaining cell viability or antigen production under high-glutamate conditions?