Figure 6.

Model illustrating the impact of extracellular D-arginine in shaping the environmental microbial biodiversity. NCDAAs production (that is, D-Arg), by Bsr+ bacteria works as a powerful bactericidal effector against competing microbes inhabiting the same niche. The inhibitory effect of D-Arg on bacterial growth bias the microbial biodiversity towards the proliferation of tolerant species, even when these organisms do not encode broad-spectrum racemases (Bsr−), establishing new relationships within the community.