Linkage between Culturable Mineral-Weathering Bacteria and Their Weathering Effectiveness Along a Soil Profile

In this study, we used culture-dependent methodology to characterize the weathering effectiveness and community of culturable mineral-weathering bacteria in an ultisol profile. A total of 261 isolates were obtained and found to have the ability to weather biotite. The proportions of the highly effective Si and Al solubilizers were significantly higher in the D and E horizons than in the A, B, C, and F horizons, while the A, B, C, and F horizons had the similar proportion of the highly effective Si solubilizers. The B and F horizons had the lowest proportion of the highly effective Al solubilizers. The D horizon had the maximum proportion of the highly effective Fe solubilizers. Lowest proportion of the highly effective Fe solubilizers was observed in the A and F horizons. The 261 mineral-weathering isolates were affiliated with 39 bacterial species within 19 genera. Burkholderia anthina from the A and B horizons, Burkholderia stabilis from the C, D, and E horizons, and Curtobacterium citreum from the F horizon had the significantly higher ability to release Si, Al, and Fe from biotite. The results showed the diverse mineral-weathering bacteria and the linkage between the weathering species and their weathering effectiveness along a soil profile.