What do bacteria do that is especially helpful to plants?
Bacteria can be especially helpful to plants by enriching the soil in which the plants are growing. This enrichment provides key molecules plants need to survive and thrive. The function of bacteria can effect both water and nutrient availability in the soil. Some specific examples include nitrogen-fixing bacteria. These types of bacteria actually infect the roots of some plants in a mutualistic way. In this relationship, the plant provides carbon compounds necessary for the bacteria, while the bacteria takes nitrogen from the air and converts it into a useable form for the plant. Following the death of the plant, during decomposition, nitrogen from these bacteria remains in a useable form and increases nitrogen levels in nearby soil. Another important example of helpful bacteria are a group known as actinomycetes. Actinomycetes are able to breakdown difficult to decompose compounds such as cellulose from decaying plant matter. This degradation again enriches the soil leading to better conditions conducive to plant growth. Many other examples of bacteria helping to enrich soil, making it more fertile for growing plants, also exist. Hope this helps!