Upper limit of pH enabling growth in Luria-Bertani broth

Value 9 Unitless
Organism Bacteria Escherichia coli
Reference Sezonov G, Joseleau-Petit D, D'Ari R. Escherichia coli physiology in Luria-Bertani broth. J Bacteriol. 2007 Dec189(23):8746-9 p.8747 left column bottom paragraphPubMed ID17905994
Primary Source [8] Neidhardt, F. C., J. L. Ingraham, and M. Schaechter. 1990. Physiology of the bacterial cell. Sinauer Associates, Sunderland, MA.
Method P.8746 right column 3rd paragraph: "The widely used wild-type E. coli K-12 strain MG1655 (ref 1), which has been sequenced and annotated (refs 2, 10), was chosen for this study. An overnight culture in Luria-Bertani broth was diluted 5,000-fold in 250 ml fresh medium in a 1-liter Erlenmeyer flask and cultivated in a shaking water bath (180 rpm) at 37°C. The OD600 and number of cells per milliliter were monitored." P.8746 left column top paragraph: "The recipe for Luria-Bertani broth is as follows. Combine 10 g of tryptone, 5 g of yeast extract, 10 g of NaCl, and 1 liter of distilled water adjust the pH to 7.0 with 1 N NaOH and autoclave the mixture for 25 min at 120°C. The tryptone used is a pancreatic digest of casein from cow's milk, and the yeast extract used is an autodigest of Saccharomyces cerevisiae."
Comments P.8747 left column 3rd paragraph: "A culture of MG1655 was grown for 24 h in Luria-Bertani broth (final OD600 of 6.49). The bacteria were then removed by centrifugation and filtration. [Investigators] call this conditioned medium LB*." P.8747 left column bottom paragraph: "The pH of LB* is routinely near 9. E. coli is unable to grow when the external pH exceeds 9 (primary source), so the cause of growth arrest could be the high pH rather than a lack of carbon. Since growth on glucose lowers the pH, the addition of glucose may permit growth resumption in LB* by acidification of the medium rather than by providing a carbon source. To determine whether growth in Luria-Bertani broth stops for lack of carbon or because of high alkalinity, [investigators] neutralized a sample of LB* with HCl. MG1655 was still unable to grow in it (OD600 of 0.02 in 24 h). Thus, growth in Luria-Bertani broth is limited by the availability of utilizable carbon sources, not by the high pH."
Entered by Uri M
ID 103515