Variovorax
Variovorax species have many diverse roles in their environmental surroundings, a noticeable one being promoting plant growth. There is a variety of mechanisms by which the bacteria can accomplish this, including the preventing of plant pathogens being produced, reducing the amount of stress a plant undergoes, and also increasing the number of nutrients that are available. Other roles can also be witnessed, including the cycling of various elements across a range of environments including arsenic. It is thought to oxidise As (III) to As (V) via a detoxification mechanism.