Involvement of a phosphate starvation inducible glucose dehydrogenase in soil phosphate solubilization by<i>Enterobacter asburiae</i>

Abstract

A glucose dehydrogenase (GDH) that is induced 5-fold by phosphate starvation, has been characterized from a bacterium isolated from alkaline Indian vertisol soils. The bacterium was identified as Enterobacter asburiae based on 16S rRNA analysis. Concomitant with GDH induction, glucose was oxidized and secreted as gluconate (50 mM). Excretion of this acid caused a reduction in soil pH and the release of phosphate and iron. Mutants deficient in GDH activity failed to release phosphate from alkaline soils indicating that GDH activity is required to solubilize phosphate.