Competition for iron also serves as a strong selective force determining the microbial population in the rhizosphere. Several studies show that PGPR exert their plant growth-promoting activity by depriving native microflora of iron. Although iron is abundant in nature, the extremely low solubility of Fe at pH 7 means that most organisms face the problem of obtaining enough iron from their environments. To fulfill their requirements for iron, bacteria have developed several strategies, including the reduction of ferric to ferrous ions, the secretion of high-affinity iron-chelating compounds, called siderophores, and the uptake of heterologous siderophores. "P. vortex's" genome, for example, harbors many genes which are employed in these strategies, in particular it has the potential to produce siderophores under iron-limiting conditions. Despite the increasing interest in "Paenibacillus" spp., genomic information of these bacteria is lacking. More extensive genome sequencing could provide fundamental insights into pathways involved in complex social behavior of bacteria, and can discover a source of genes with biotechnological potential. "Candidatus "Paenibacillus glabratella causes white nodules and high mortality of "Biomphalaria glabrata" freshwater snails. This is potentially important because "Biomphalaria glabrata" is an intermediate host of schistosomiasis. Several "Paenibacillus" species can form complex patterns on semisolid surfaces. Development of such complex colonies require self-organization and cooperative behavior of individual cells while employing sophisticated chemical communication. Pattern formation and self-organization in microbial systems is an intriguing phenomenon and reflects social behaviors of bacteria that might provide insights into the evolutionary development of the collective action of cells in higher organisms. One of the most fascinating pattern forming "Paenibacillus" species is "P. vortex", self-lubricating, flagella-driven bacteria. "P. vortex" organizes its colonies by generating modules, each consisting of many bacteria, which are used as building blocks for the colony as a whole. The modules are groups of bacteria that move around a common center at about 10 µm/s. An additional intriguing pattern forming "Paenibacillus" species is "P. dendritiformis", which generates two different morphotypes – the branching (or tip-splitting) morphotype and the chiral morphotype that is marked by curly branches with well-defined handedness (see pictures).