When a colonizer casts its colonizing enzyme ability, they will spend nutrients and release some enzyme into the atmosphere. The more colonizers you have the quicker your colonizing enzyme will spread. Enemy units will take damage as they absorb the colonizing enzyme. So units can remove your enzyme effect from the environment if they absorb enough of it.
Stats that affect Colonizing Enzyme are: Potency: Increases damage, decreases amount of enzyme released, and cost Metabolism: Decreases cost and damage Capacity: Increases the amount of enzyme released