Fig. 2

Mineral precipitation of urease-expressing strains of B. subtilis. A Precipitation on LBC media. B Precipitation on B4 media. Both media were supplemented with urea and xylose. Urease-producing strains W∆-H-BpU and W∆-U-H-BpU were spotted onto solid precipitation media and incubated at 30 °C. Mineral precipitation was monitored for up to 9 days and images of the colonies taken with a stereomicroscope at the time points indicated above the panels. Mineral crystals formed on the colony surface are indicated with white arrows, crystals formed on the surrounding agar by grey arrows. Scale bars represent 1 mm in size. The results are a representative series from two to three biological repeats