INFLUENCE OF GROWTH-RATE AND NUTRIENT LIMITATION ON MONOBACTAM PRODUCTION AND PEPTIDOGLYCAN SYNTHESIS IN PSEUDOMONAS-AERUGINOSA

The effects of growth rate and nutrient limitation on monobactam produ ction, peptidoglycan content and mean cell length in Pseudomonas aerug inosa was studied using continuous culture techniques. All three param eters increased progressively with growth rate, a greater response bei ng shown under carbon limitation compared to that occurring under nitr ogen limiting conditions. interestingly, monobactum production mirrore d peptidoglycan synthesis. In addition, the monobactam exhibited a bro ad rang of antibacterial activity and bound preferentially to PBP 1A i n the producing organism. Moreover, addition of the monobactam to a gr owing culture inhibited cell wall synthesis. These results are discuss ed in relation to the control and regulation of peptidoglycan synthesi s.