Edinburgh Napier University

  Although the starvation or non-growth state is probably the most common physiological state of bacteria, it has been studied in relatively few organisms. In spite of its
importance in pathogenesis, bioremediation and several industrial processes, limited research has been performed on Rhodococcus under starvation/stationary phase
conditions. The objectives of this study were to analyse the physiological adaptation of Rhodococcus erythropolis SQ1 to starvation/stationary phase, and to generate and
screen a bank of mutants to identify genetic elements involved in this adaptation.

It was found that R. erythropolis SQ1 can survive for at least 43 days in LB and distilled water, and 65 days in chemically defined medium (CDM) containing high (1 %
w/v) or low (0.1 % w/v) glucose concentrations. Early stationary phase R. erythropolis SQ1 cells grown in 0.1 % glucose also exhibited enhanced resistance to heat and
oxidative stress compared with exponential phase cells. A mutant bank of 898 R. erythropolis SQ1 mutants was generated and screened; four mutants were of particular
interest. The culturability of mutants 4G6 and 10D3 dropped to