Milk Powder for Biotechnology and Microbiology

Skim milk powder is widely used in microbiology as a nutrient source in microbial culture media. It provides a complex mixture of nutrients, including protein, lactose, and minerals, that support the growth of a variety of microorganisms. Skim milk powder is commonly used in media formulations for the cultivation of lactic acid bacteria, including Streptococcus and Lactobacillus species. It can also be used as a supplement in media for the growth of other microbial cells, including fungi, yeasts, and some bacteria that utilize milk proteins as a nutrient source. Additionally, skim milk powder has the advantage of being shelf-stable and easily rehydratable, making it a convenient and cost-effective source of nutrients for microbial cultivation.

Skim milk powder is usually used as an ingredient in many microbial culture media for the growth and identification of bacteria, yeasts, and molds from various pharmaceutical, environmental, food and beverage samples. Furthermore, it is described in the EN ISO 6887-4:2017 to be used as pre-enrichment broth for the detection of Salmonella spp. and STEC when testing cocoa and cocoa containing products (use 100 g/l; sterilize after reconstitution). As an ingredient in culture media Skim milk powder is usually employed in concentrations of 0.1 to 1.0%.

Replaces: 1.15363.9017

Assay protein (ex N, calc. on dried substance): ≥ 35 %
Lactose (enzymatically): 40 - 52 %
pH-value (1 %; water): 6 - 7
Fats: ≤ 1.5 %
Free acid (as lactic acid): ≤ 2 %
Ash (800 °C): ≤ 10 %
Water (according to Karl Fischer): ≤ 5.0 %
Suitability for microbiology: passes test
Microbiological test: passes test
Identity (NIR): passes test

Rehydrating the Skim milk powder, or using it for the preparation of culture media, the milk powder should be gently added to water with proper stirring to make sure that no clumps are present in the rehydrated skim milk or the prepared media