SUMMARY: Marburg was found to produce an appreciable amount of an antibiotic in a synthetic medium. Antibiotic activity was produced in parallel with cell growth, and production stopped at the end of exponential growth. When the synthetic medium was supplemented with a small amount of Casamino acids, however, antibiotic was made only at the end of growth and in lesser amounts. The ability of cells to produce the antibiotic increased when stringent ( = wild-type) cells underwent a partial stringent response. These conditions also initiated extensive sporulation. An isogenic relaxed () strain produced little antibiotic activity, which decreased under partial amino acid deprivation. In cells, the addition of a low concentration of chloramphenicol, which reduces ppGpp synthesis, also reduced antibiotic synthesis in both normal and amino acid-starved bacteria, without appreciably affecting their growth rate. Guanosine starvation of a mutant initiated sporulation, but decreased antibiotic production. The results show that the stringent response initiates both sporulation (differentiation) and antibiotic production (secondary metabolism), but by different mechanisms. It appears that sporulation results from a decrease of GTP, whereas antibiotic synthesis results from a different effect of the stringent response.


Article metrics loading...

Loading full text...

Full text loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error