How do earthworms affect the microbial community during vermicomposting for organic waste recycling?

Earthworms, characterized as “ecosystem engineers,” impact the soil microbial population and function by boosting the microhabitat, feeding and transporting microorganisms, and increasing the surface area of organic matter. The multiscale holes produced by earthworm activities increase soil porosity and aeration, supporting microorganism development and reproduction. In addition, earthworms transform complex organic components into microbe-accessible nutrients by feeding on, compacting, and mixing the soil, which increases the decomposition and cycling of soil's essential constituents such as carbon, nitrogen, and phosphorus, enhancing the soil's biological productivity. Vermicomposting is the process through which earthworms and microorganisms break down organic waste. Recent research highlights the importance of the earthworm digestive tract as a major influence on microbial communities during vermicomposting. It has been demonstrated that adding these annelids to new organic matter modifies the activity level and functional diversity of microbial populations. Furthermore, microbial succession in the gut and cast of earthworms and soil is crucial for decomposing organic wastes. This chapter examines how the microbial population changes during vermicomposting to better understand vermicompost's role as an additive to improve soil quality.