Earthworm castings are teeming with a diverse array of microorganisms and enzymes that contribute to their beneficial properties.  Minerals also play an important role in the nutrients provided to the soil by earthworm castings. 

Some of the microorganisms commonly found in earthworm castings include:

BACTERIA: Various types of bacteria, including beneficial nitrogen-fixing bacteria, decompose organic matter and convert nutrients into forms that are readily available to plants.

FUNGI: Mycorrhizal fungi form symbiotic relationships with plant roots, aiding in nutrient uptake and enhancing plant growth.

PROTOZOA: Protozoa help break down organic matter, control harmful bacteria, and improve soil structure.

ACTINOMYCETES: Actinomycetes decompose organic materials and produce enzymes that break down complex compounds.

As for enzymes, earthworm castings contain a range of enzymes that aid in the decomposition of organic matter and the conversion of nutrients. 

These enzymes include:

AMYLASES: Break down starches into simpler sugars.

PROTEASES: Break down proteins into amino acids.

CELLULASES: Break down cellulose, a complex carbohydrate found in plant cell walls.

LIPASES: Break down lipids or fats into fatty acids and glycerol.

CHITINASES: Break down chitin, a component of fungal cell walls and insect exoskeletons.

These microorganisms and enzymes work synergistically to break down organic matter, enhance nutrient availability, improve soil structure, suppress harmful pathogens, and promote plant growth.

Earthworm castings are rich in various plant minerals that are beneficial for plant growth and health. Some of the key elements found in earthworm castings include:

NITROGEN (N): Nitrogen is essential for plant growth and is a crucial component of proteins, enzymes, and chlorophyll.

PHOSPHORUS (P): Phosphorus is important for root development, flowering, and fruiting. It also plays a role in energy transfer within plants.

POTASIUM (K): Potassium helps with overall plant growth, photosynthesis, and the regulation of water uptake and retention. 

CARBON (C): Carbon is essential for plants because it serves as a building block for organic molecules, particularly through the process of photosynthesis.  Also, it is very important for the formation of the various cell walls of the plant. 

CALCIUM (Ca): Calcium is essential for cell wall structure, root development, and proper nutrient uptake by plants.

MAGNESIUM (Mg): Magnesium is an essential component of chlorophyll and is crucial for photosynthesis.

TRACE MINERALS: Earthworm castings also contain various trace minerals such as iron, manganese, zinc, copper, and others. These minerals are necessary for plant growth in small amounts.

Altogether the microorganisms, enzymes, minerals, other elements and compounds found in earthworm castings make them a valuable soil conditioner and soil enhancer. 
(Apart from these nutrients, earthworm castings also contain beneficial microorganisms and enzymes that contribute to soil health and enhance nutrient availability to plants.) These combined factors make worm castings a valuable organic fertilizer and soil amendment.