Fig. 1: Deletion of the pst phosphate-specific transport genes drops biolixiviant pH by as much as 0.29 units, and improves bioleaching efficiency by up to 30.1% from allanite ore.

A Effects of transposon disruption (δ) or deletion (Δ) of pst genes on the biolixiviant pH. Stars denote significant differences between disruption and deletion strains with a p-value < 0.01. The pH of the biolixiviants produced by all disruption and deletion strains was significantly different than wild type (wt) with p-values < 0.001. B Effects of disruption or deletion of pst genes on REE-bioleaching efficiency. Deletion of the ABC-type phosphate transporter ATP-binding protein PstB increases bioleaching by 29.3% over wild-type. Meanwhile, deletion of the ABC-type phosphate transporter substrate-binding protein, PstS increases bioleaching by 30.1% over wild-type. Stars denote significant improvement in total REE-bioleaching as compared with wild-type G. oxydans, p < 0.05. For all experiments, strains were tested in triplicate, and results are demonstrative of multiple tests. Comparisons were made in Microsoft Excel with a two-tailed homoscedastic t-test. All data for this figure, including p-values, can be found in Supplementary Data S1⁴⁵.