Inorganic substances, such as metal-ions, play a vital role in the functioning of cells. They are acting as prosthetic groups in enzymes, structuring protein conformations, are involved in the DNS transcription and much more. These micro nutrients are usually required only in trace quantities, and are even toxic at higher levels, but a deficiency will invariably lead to a malfunctioning of the cell. In the case of brewers yeast, this might by expressed by low growth and fermentation rates or an excessive formation of fermentation by-products, which certainly cannot be accepted. A short and thus costeffective fermentation time is essential for the modern brewing process, and to ensure that, a deeper understanding of the effect of metal-ions in the wort is necessary.

Effect of zinc and other metals on yeast growth and fermentation