King FG Agar
King FG Agar is used for the enumeration of psychotrophic microorganisms in foods and drinks. Psychotrophic organisms are extremophile organisms that are capable of grow and reproduce in low temperatures ranging from 0 to 20 ºC and are widespread in natural environments and in foods. Psychrotrophic microorganisms are well-known for their degradative activities in foods. Some are pathogenic or toxinogenic for humans, animals or plants. Organisms in this group are Pseudomonas, Achromobacter, Alcaligenes, Flavobacterium, and Aeromonas, as well as other species of enterobacteriaceae from the genera: Escherichia, Proteus, Klebsiella, Enterobacter and Hafnia. These are all Gram-negative bacteria.
Peptone provides nitrogen, vitamins, minerals and amino acids essential for growth. Maltose is the fermentable carbohydrate that gives carbon and energy. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Potassium phosphate and magnesium sulfate provide minerals and ions and act as a buffer. Bacteriological agar is the solidifying agent. Crystal violet inhibits Gram-positive bacteria.
