Calcium and phosphorus-bearing granules in Lake Geneva: morphological typology and composition - Methodology and supporting data

Phosphorus-bearing granules (PBGs), mainly composed of calcium and phosphorus, are common in microorganisms and play roles in energy transfer and calcium regulation. This study analyzed over 1,400 energy dispersive X-ray spectroscopy (EDXS) analyses of organic clusters from Lake Geneva, creating a four-type classification based on morphology and composition. Results show bimodal phosphorus and calcium distributions, with significant variability suggesting distinct subpopulations influenced by organism diversity and environment. Statistical analyses linked PBG size and composition to host type, shaped by magnesium content and calcium-phosphorus ratios. Transmission electron microscopy (TEM) confirmed structural homogeneity within PBGs and morphological contrasts between types. Overall, findings reveal PBG complexity and their potential role in calcium and phosphorus cycling in freshwater systems. The methodology and data used can be found here.