Xanthomonas campestris is a type of bacteria that primarily affects plants, particularly those in the Brassicaceae family, such as cabbage and broccoli. It is known for causing black rot, a disease that leads to yellowing and wilting of leaves, ultimately affecting crop yield and quality. This bacterium is rod-shaped and can spread through water, soil, and infected plant material. It produces a polysaccharide known as xanthan gum, which is widely used in the food industry as a thickening agent and stabilizer. Understanding Xanthomonas campestris is important for managing plant diseases and ensuring agricultural productivity.