DOI: 10.5176/2251-2489_ BioTech14.59
Authors: Mohamed M Bumadian, Michael P. Williamson, D. James Gilmour
Abstract: Compatible solutes can be synthesized de novo (osmolytes) or taken up if present in the medium (osmoprotectors). Glycine betaine (commonly named betaine) is only synthesized de novo by phototrophic salt tolerant bacteria. However, if betaine, or its precursor choline is present in the environment then heterotrophic halotolerant bacteria utilize transport systems to accumulate betaine (4). The de novo synthesis of compatible solutes was monitored by NMR spectroscopy. In LB medium, betaine was found in all spectra for K. pneumoniae and increased with increasing salinity from 0.17- 3.5 M NaCl. Ectoine was only found above 2 M NaCl. In contrast, in M9 medium, betaine was absent in all spectra for K. pneumoniae Glutamate was present at 0.5 M NaCl, but only ectoine was present at high salt concentrations 0.75, 1 and 1.25 M NaCl.
Keywords: compatible solutes, de novo synthesis, Klebsiella pneumoniae
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