Studies on the Formation of Bacitracin by Bacillus licheniformis: Effect of Glucose

Abstract

SUMMARYThe production of bacitracin by Bacillus licheniformis closely paralleled growth in a synthetic medium without glucose.' Glucose inhibited bacitracin production during the first hours of growth, whereas growth was not affected. Bacitracin was produced mainly during the later stages of growth. Formation of bacitracin was apparently not under catabolite repression control by glucose since the inhibitory effect of glucose upon the early bacitracin production was prevented by neutralizing the culture fluid with CaCO,. The inhibitory effect of glucose may be due to the low pH created by its metabolism.Addition of 0.5 % glucose markedly increased the maximum titre of bacitracin.This stimulation could also be due to the effect of glucose metabolism upon the pH of the medium. The observation that peptide antibiotics are produced mainly after growth is not always true; in appropriate media they might also be produced during the phase of rapid growth.

Effect of Carbon Source on the Antimicrobial Activity of the Air Flora

“…Glucose, usually an excellent carbon source for growth, interferes with the biosynthesis of many antibiotics such as bacitracin (Haavik 1974) and actinomycin (Gallo & Katz 1972). During studies on fermentation medium development, polysaccharides or oligosaccharides are often found to be better than glucose as carbon sources for antibiotic production (Martin & Demain 1980).…”

The two‐component regulatory system BacRS is associated with bacitracin ‘self‐resistance’ of Bacillus licheniformis ATCC 10716

“…Bacillus licheniformis ATCC 10716 was maintained on Difco sporulation agar and grown for DNA isolation in rich medium (Luria–Bertani) at 37 °C under aerobic conditions. For bacitracin production and analysis of stress response, B. licheniformis was grown in either Difco sporulation medium, Luria–Bertani medium, or M20 medium [44], and growth was monitored by measuring D 600 . RNA isolation was performed with cells grown in Difco sporulation medium and M20.…”

“…M20 medium [44] was inoculated with the B. licheniformis strains and incubated with shaking for an appropriate time at 37 °C. Cells were harvested by centrifugation and the supernatant was extracted with 2 volumes of n ‐butanol.…”

Antibiotic-Producing Bacteria as a Possible Defence of Birds against Pathogenic Microorganisms

“…Most of these bacteria, as those of the genera Enterococcus, Staphylococcus [77] and Streptomices [78], are known producers of antibiotic substances and, therefore, if present in transported-to-the-nest feathers they could play a role preventing the establishment of other bacteria within the nest environment. For instance, Bacillus licheniformis is perhaps the most common feather degrading bacteria species in feathers of wild birds (Burtt and Ichida 1999) and, apart from its pathogenic activity on avian feathers, it is also known to produce antimicrobial substances [79][80][81], that are active not only against different strains belonging to the genera Bacillus, Corynebacterium, Enterococcus, and Micobacterium, but also against amoebas [82] and fungi [83,84]. Consequently, the use of feathers by many species of birds for nest lining could in fact be a growing culture of B. licheniformis and some other bacteria that prevent the establishment of pathogenic bacteria in the nest environment.…”