Abstract
Hemorrhagic septicemia (HS), caused by Pasteurella multocida serotype B:2, remains a major transboundary disease of cattle and buffalo, particularly in tropical regions. Efficient vaccine production requires high-density biomass generation under controlled and scalable fermentation conditions. This study designed as a sequential process-development and optimization study aimed to optimize industrial-scale cultivation of P. multocida B:2 using a 150-L bioreactor system with S1-S5 samples (n = 5) representing independent fermentation runs from analytical measurements through media selection, fed-batch supplementation, pH control, and thermal preconditioning strategies. Comparative batch cultivation demonstrated superior biomass production in tryptose phosphate broth (TPB) compared to casein sucrose yeast (CSY) medium (OD600 1.57 vs 0.76; p 2.5-fold increase in biomass productivity compared to conventional batch cultivation. These findings provide a scalable and cost-effective fermentation framework for improved commercial production of HS vaccine antigen.