Gistex LS Powder

Yeast peptone, yeast extract or yeast peptide: how to choose

All three come from yeast and are animal-free; they differ in molecular size and composition. Yeast extract is the water-soluble fraction after autolysis, highest in free amino acids, B vitamins and nucleotides, and is used to supply growth factors. Yeast peptone is mainly short and medium peptides with a steadier nitrogen release, suited to fermentations that need nitrogen over a long run. Yeast peptides are smaller still and taken up quickly. Fastidious organisms such as lactic acid bacteria and bifidobacteria usually get both: peptone for nitrogen, extract for growth factors. Grades within a range differ in total nitrogen, amino nitrogen ratio, nucleotides and clarity in solution; see the specification sheets.

Product highlights

• Available in 20 kg, from laboratory to industrial scale
• COA, specification sheet, and technical data sheet available; samples on request
• Shipped from Taiwan with reliable supply

Frequently asked questions

Further reading

• A yeast peptone scale-up example from the patent literature: one nitrogen source from 3 L to 500 LA granted US patent uses 2.0% Yeast Peptone GLS as the fermentation nitrogen source in its examples, across three culture stages of 3 L, 50 L and 500 L. This note sets out the formulation and conditions the patent discloses, and what such literature can and cannot tell you about scale-up.