Expression of Vitreoscilla hemoglobin gene in different organisms: a new approach to increase the efficiency of various biological processes

Vitreoscilla hemoglobin (VHb), a 15,775 Da oxygen-binding protein, enhances intracellular oxygen transfer, improves the efficiency of oxygen use, and promotes organism growth and the desired metabolite production. Researchers have investigated VHb gene expression for two decades to enhance aerobic biological processes in diverse organisms. This review examines the protein structure, biochemical characteristics, genetic structure, cellular mechanisms of activity, and protein engineering of VHb. It then assesses the impact of VHb expression on the performance improvement of bacteria, fungi, plants, and mammalian cells in various biological processes. Finally, the article specifically discusses the VHb gene expression strategies in Streptomyces.