Rapid photometric assay of growth of Mycoplasma mycoides subsp. capri.

A new spectrophotometric technique for evaluation of early growth in liquid culture of Mycoplasma mycoides subsp. capri has been developed. As turbidity does not appear until after incubation to 18 h the method utilizes the change in absorbance of the medium at 550 nm to monitor growth. The change in absorbance of the medium (which contains phenol red) occurs when the pH changes due to microbial growth. For measurement of growth at later stages when turbidity is proportional to number of colony forming units, two other wavelengths (450 nm and 700 nm) have been suggested.