It can absorb and become saturated with oxygen at oxygen partial pressures as low as 19 mm Hg. Earthworms encourage the growth of microorganisms in their gut by providing ideal conditions therein. Bacteria and actinomycetes which are important in waste degradation increase exponentially along the length of the tubular bioreactor, reaching densities about 1000 greater than in the surrounding soil. However, E. coli, salmonella and other pathogens are destroyed due to competition from the active microflora and intestinal secretions. Most of the human pathogens are anaerobic and cannot survive in the highly aerobic micro-environment created by the earthworms.
Earthworms produce castings with balanced plant nutrients.
Vermicastings also have immobilised microflora which continue their function in the soil. Vermicastings are rich in vitamins, enzymes, antibiotics and growth hormones.