Pectin drives microbial phosphorus solubilization in soil: Evidence from isolation-based and community-scale approaches

A considerable part of soil phosphorus is bound to metal cations or metal oxides, and cannot be used in these forms by soil microbes and plants. Phosphate-solubilizing bacteria (PSB) are abundant in pectin-rich rhizosphere, and their pectin-degrading activity has been reported. Therefore, we hypothesized that pectin activates PSB and promotes soil phosphorus solubilization. To test this hypothesis, we first tested the phosphate-solubilizing activity of pectin-degrading bacteria. PSB were more frequently isolated from pectin-containing medium, compared with other media (P