Vanadium is commonly used in the preparation of metal alloys, and is moderately toxic to humans (ToxFAQs: Vanadium). Vanadium is considered to be an essential trace element, but its biological function is not completely understood. The accumulation of vanadium in blood cells (vanadocytes) of tunicates (sea squirts, class Ascidiacea) was described in the early twentieth century (Henze, 1911; reviewed by Smith et al, 1995)). Vanadium accumulation in tissues of another marine animal, Pseudopotamilla occelata (fan worm, class Polychaeta), was discovered in 1993 (reviewed by Ishii et al, 1995). The purpose of vanadium accumulation in these organisms is not known.

Microbial enzymes containing vanadium were first identified in 1986 and are known to represent three enzyme classes: haloperoxidases (reviewed by Vilter, 1995), nitrogenases (reviewed by Eady, 1995), and nitrate reductases ( Antipov et al, 2003). Some bacteria and fungi can reduce vanadium(V) to vanadium(IV) and possibly vanadium(III) (reviewed by Lovley, 1993), and Pseudomonas isachenkovii can use vanadate (VO₄^3-) as a terminal electron acceptor during anaerobic growth (Antipov et al, 2000). However, the mechanisms of microbial vanadium reduction are not known, and few microbial taxa have been assayed for vanadium reduction.

In the absence of phosphate, the fungus Neurospora crassa was shown to import vanadate ions via a high-affinity phosphate transport system (Bowman, 1983). Vanadium bioaccumulation has been described in Gram-negative bacteria (Mueller et al, 1988; Hernandez et al, 1998) and yeast (Willsky et al, 1985).

For more information:

Search Medline for vanadium metabolism AND bacteria

Henze M. Untersuchungen uber das blut der Ascidien. I. Mitteilung. Die Vanadiumverbindung der Blutkorperchen. Hoppe-Seyler's Z. Physiol. Chem. 1911;72:494-501.

Ishii T., Nakai I., Okoshi K. Biochemical significance of vanadium in a polychaete worm. Metal Ions in Biological Systems 1995;31:491-509.

Mueller A., Schneider K., Erfkamp J., Wittneben V., Diemann E., Eaton A. N. Vanadium accumulation in the nitrogen-fixing hydrogen bacterium Xanthobacter autotrophicus. Naturwissenschaften 1988;75:625-27.