Applications of the VHb Gene vgb for Improved Microbial Fermentation Processes

Dissolved oxygen (DO) plays an important role in cell growth, especially in industry-scale microbial production. To alleviate the defects of hypoxic conditions, Vitreoscilla hemoglobin (VHb) has been used to enhance respiration and energy metabolism by promoting oxygen delivery. Heterologous expression of VHb in a variety of hosts has been shown to improve cell growth, protein synthesis, metabolite productivity, and bioremediation under oxygen-restricted conditions. In this chapter, many well-studied areas are presented to illustrate the potential of VHb application in microbial metabolic engineering industry. Also, applications of the vgb promoter have been discussed.