The relationship between earthworms (including the various composting worms) and the aerobic microbes or bacteria that accompany them is one of nature’s most perfect examples of symbiosis. The worms have millions of beneficial bacteria associated with them, both externally, on their skin, in the mucus secretions that keep them moist and also swarming internally inside their gut. These microbes, are essential for the processing of the worms’ raw “food” material into a form that the worms can actually ingest into their bodies.
Worms have no teeth, bills or jaws, nor a true stomach and rely solely on the bacteria swarming around them to actually break down the foodstuff that we put in our bins. Prior to ingestion by the worms, the foodstuff is deconstituted and altered considerably by the microbes, such that it can be sucked up by the worms as a slimy paste-like substance. It goes directly into their gizzard and passed onward through the worms’ very rudimentary digestive tract, together with masses of the bacteria, swarming within the slime.
Inside the worm’s gut the breakdown process continues and the worms’ digestive tract, provides a perfect environment for the ingested bacteria, who multiply further and continue to convert the complex cell structure of the original foodstuff into its basic elements and compounds, altering it into a simpler form that can be used directly by both the worms and the bacteria for nourishment. These simple elements and compounds provide the basic building blocks to sustain both worms and bacteria and are reconstituted according to the messages carried by the DNA to build up the complex cell structures that create the living physiology of both worm and bacterium. A true win / win situation for both organisms.
Large numbers of these bacteria are released back into the worm bin, together with the waste products in the faeces or castings – our vermicompost. The microbes will have multiplied in the ideal environment of the worm’s gut and now, greatly increased in numbers, are once again ready to attack new food sources and start the process all over.
Of great importance, these waste products, or vermicompost, excreted by the worms have been thoroughly processed by the microbes and are now in the form of simple elements and compounds, that are readily taken up by our garden plants, providing a highly nutritious food for them. Moreover any dangerous toxins and infected material would have been simultaneously neutralised by the bacteria within the worms gut, as complex forms of pathogenic material are also broken down into simpler, more basic (harmless) components by the microbes. In the soil the process continues and worm compost, with its load of beneficial bacteria will also tend to improve the health of soil around the roots of plants by removing pathogens. This is the beauty of using worms and their huge army of tiny microscopic helpers, for your composting.
What about the effect of the CO2 released as a result of the biological activity of the micro-organisms on global warming?
It is true that the microbes associated with worm farming do release some CO2. However if the organic material (waste) was left to putrify anaerobically – as in a landfill, then methane would be given off by anaerobic bacteria, which is a far greater threat to the environment.