Solid Gel

//Solid Gel
  • This medium is recommended for the detection and enumeration of yeasts and moulds in food and dairy products. It can also be used for the cultivation of fungi although with the prolonged incubation necessary cultures may become overgrown by bacteria. The low pH (5.6) suppresses the growth of most bacteria and the low mineral content ensures good pigment production by fungi where appropriate.
  • This medium can be used as a screening method for the differentiation of Enterobacteriaceae based on the ability of some species to utilise citrate as a sole source of carbon. It is often used as a screening test for Klebsiella pneumoniae (Positive reaction) while Escherichia coli is negative. Other uses included distinguishing between species of citrate positive Salmonellae (e.g. Salmonella enteritidis) and those that are negative (e.g. Salmonella typhi and Salmonella paratyphi A). The medium is inoculated by stabbing the organism (in pure culture) into the medium. A positive result produces a change of colour from green to bright blue and a negative reaction leaves the colour unchanged.