Trace elements Microbes require very small amounts of other mineral elements, such as iron, copper, molybdenum, and zinc these are referred to as trace elements. most are essential for activity of certain enzymes, usually as cofactorsTrace Elements Microbes require very small amounts of other mineral elements, such as iron, copper, molybdenum, and zinc; these are referred to as trace elements. Most are essential for activity of certain enzymes, usually as cofactors