Grouping of Mycobacteria by Utilization of Propylene Glycol, Glucose, Fructose, and Sucrose as Sole Carbon Sources

Abstract

Utilization of propylene glycol, glucose, fructose and sucrose by mycobacteria were tested on the following medium: (NH₄)₂SO₄, 2.64g; KH₂PO₄, 0.5g; MgSO₄-7H₂O, 0.5g; Purified agar (Wako), 30.0g; and distilled water, 1000ml. Propylene glycol was added at concentration of 0.5M, and sugars at concentration of 0.05M. The pH was adjusted to 7.0 by addition of 10% KOH. The media were incubated with one loopful of the stack cultures and incubated at 37°C. Growth was observed after three weeks in comparison with growth on control medium containing no carbon source.
Among mycobacteria tested (Table 1), M. smegmatis, M. fortuitum and M. parafortuitum utilized propylene glycol as sole carbon source, but not all strains. M. phlei and other rapid growers did not utilize it.
All strains of M. fortuitum, M. parafortuitum, M. smegmatis, and M. phlei utilized both glucose and fructose as sole carbon sources. Sucrose was utilized by a few strains of scotochromogens, M. fortuitum, and M. smegmatis. M. kansasii utilized only glucose.
Among M. avium, nonphotochromogens and scotochromogens, M. avium did not utilize all sugars, twelve of nineteen nonphotochromogens utilized only glucose, and fonrteen of fifteen scotochromogens utilized glucose. Five strains of scotochromogens utilized also fructose or sucrose or both (Table 2).