Recent Advances in the Physicochemical Properties and Biotechnological Application of Vitreoscilla Hemoglobin

Abstract

Vitreoscilla hemoglobin (VHb), the first discovered bacterial hemoglobin, is a soluble heme-binding protein with a faster rate of oxygen dissociation. Since it can enhance cell growth, product synthesis and stress tolerance, VHb has been widely applied in the field of metabolic engineering for microorganisms, plants, and animals. Especially under oxygen-limited conditions, VHb can interact with terminal oxidase to deliver enough oxygen to achieve high-cell-density fermentation. In recent years, with the development of bioinformatics and synthetic biology, several novel physicochemical properties and metabolic regulatory effects of VHb have been discovered and numerous strategies have been utilized to enhance the expression level of VHb in various hosts, which greatly promotes its applications in biotechnology. Thus, in this review, the new information regarding structure, function and expressional tactics for VHb is summarized to understand its latest applications and pave a new way for the future improvement of biosynthesis for other products.

Improving Degradation of Polycyclic Aromatic Hydrocarbons by Bacillus atrophaeus Laccase Fused with Vitreoscilla Hemoglobin and a Novel Strong Promoter Replacement

“…Therefore, the amount of dissolved oxygen in the reaction plays a critical role in regulating the catalytic efficiency of laccases [ 16 ]. Vitreoscilla hemoglobin (VHb), which is encoded by the vgb gene, is an oxygen-binding protein that increases the oxygen supply, thereby enhancing cell growth, product synthesis, and stress tolerance, and has been used in the field of metabolic engineering for microorganisms, plants, and animals [ 30 ]. We hypothesized that the dissolved oxygen level should increase through the fusion of vgb and LacH5, leading to an increase in the catalytic efficiency of LacH5.…”

“…We hypothesized that high dissolved oxygen levels should provide more electron acceptors, thus accelerating the reaction rate and improving the catalytic efficiency of LacH5. VHb was the first soluble heme-binding protein discovered from a bacteria with a fast rate of oxygen dissociation and is used widely in various biological research fields, such as biochemical engineering, metabolic engineering, and bioremediation [ 30 , 37 ]. In this study, two Vgb-based LacH5 fusion constructs were prepared to increase the amount of dissolved oxygen and thus enhance the catalytic efficiency of LacH5.…”

Potential of Escherichia coli Probiotics for Improved Health and Disease Management

“…Vitreoscilla hemoglobin (VHb) with a high affinity for oxygen facilitates the survival and functionality of bacteria under microaerobic conditions [54] promoted colonization of genetically modified E. coli in the gut. E. coli 16 double transformants of gfp and Vitreoscilla hemoglobin (vgb) genes at 10 8 cfu/g were present in the rat fecal matter after 70 days of oral administration, while Ec16 gfp was not found after 48 days [37].…”

Application of metabolic engineering to enhance the content of alkaloids in medicinal plants

“…Vhb is a bacterial hemoglobin that interacts with terminal oxidase to provide enough oxygen for cell growth. It has been used to metabolic engineer plants, microorganisms and animals to increase cell density, enhance products biosynthesis and stress tolerance under oxygen-limited conditions ( Yu et al, 2021 ). Table 1 provides more examples of foreign enzymes reported to be useful in alkaloid production.…”