Rhizobia are a group of bacteria that form a symbiotic relationship with the roots of leguminous plants, such as soybeans and clover. These bacteria are capable of fixing atmospheric nitrogen, converting it into a form that plants can use for growth. This process is essential for soil fertility and helps reduce the need for chemical fertilizers. When rhizobia infect the roots of their host plants, they create specialized structures called nodules. Inside these nodules, the bacteria thrive and carry out nitrogen fixation. This partnership benefits both the plants, which receive essential nutrients, and the bacteria, which gain carbohydrates and a suitable environment for growth.