NMR studies of a bacterial cell culture medium (LB Broth): cyclic nucleosides in yeast extracts

Rayner, Michael

doi:10.1016/0378-1097(90)90154-i

Cited by 5 publications

(6 citation statements)

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“…Additionally, a resonance originates from heterogeneous phospholipids in the growth medium. This resonance has also been observed by Rayner et al (17), and its assignment was corroborated by scanning uninoculated medium (data not shown). The vacuolar and extracellular P i resonances appear on the high shoulder of the phospholipid resonance.…”

Section: Response Of S Cerevisiae To Alkaline Ph Shift For High Levesupporting

confidence: 84%

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In situ 31P nuclear magnetic resonance for observation of polyphosphate and catabolite responses of chemostat-cultivated Saccharomyces cerevisiae after alkalinization

Castro

Meehan

Koretsky

et al. 1995

Appl Environ Microbiol

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The proposed pH buffering and phosphagenic functions of polyphosphate were investigated by subjecting chemostat-cultivated Saccharomyces cerevisiae to alkalinization (NaOH addition) and anaerobiosis. The subsequent changes in intracellular phosphate-containing species were observed in situ by nuclear magnetic resonance (NMR) spectroscopy by using the NMR cultivator we developed. For the alkalinization experiments, changes in catabolite secretion were also measured in parallel experiments. Additionally, a range of potential neutralization capacity was investigated: a dilute culture and concentrated cultures with low or high polyphosphate content. The concentrated cultures displayed increased cytosolic pH and rapid polyphosphate degradation to small chains. The pH changes and extent of polyphosphate degradation depended inversely on initial polyphosphate content. The dilute culture restored extracellular pH rapidly and secreted acetate. The concentrated culture with low polyphosphate reserves also secreted acetate. In contrast to the alkalinizationinduced polyphosphate dynamics, anaerobiosis resulted in the complete hydrolysis of polyphosphate to P i , as opposed to small chains, and reduced cytosolic pH. The results and calculations suggest that the bulk of NMR-observable polyphosphate (vacuolar) degradation to short polymers conceivably contributes to neutralizing added alkalinity. In other circumstances, such as anaerobiosis, degradation serves other functions, such as phosphorylation potential regulation.

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Section: Response Of S Cerevisiae To Alkaline Ph Shift For High Levesupporting

confidence: 84%

“…3. In these spectra, a reference and an additional medium constituent appears (2Ј,3Ј-cyclic nucleosides) CP (17). As anticipated, the polyphosphate content was lower when phosphate was reduced (compare Fig.…”

Section: Response Of S Cerevisiae To Alkaline Ph Shift For High Levesupporting

confidence: 66%

In situ 31P nuclear magnetic resonance for observation of polyphosphate and catabolite responses of chemostat-cultivated Saccharomyces cerevisiae after alkalinization

Castro

Meehan

Koretsky

et al. 1995

Appl Environ Microbiol

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“…The former (top) corresponds to 7 vol % yeast suspension acquired over 8 min, while the latter spectrum (middle) is from 4 vol % yeast acquired over 6.9 min. Resonances were identified by comparison with other published spectra (e.g., den Hollander et al, 1981; Nicolay et al, 1983; Cambell‐Burke and Shulman, 1987; Rayner et al, 1990).…”

Section: Resultsmentioning

confidence: 99%

Performance Trade-offs in In Situ Chemostat NMR

1999

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Investigating cell cultures with NMR requires high cell densities to provide adequate signal-to-noise, or scans must be summed over long time periods and short-term events are lost. The mixing within a chemostat can be used to shorten the time required to acquire informative in situ NMR spectra from cell cultures. However, performance trade-offs can occur between net signal, spectral resolution, and oxygenation due to sampling volume, conductivity, gas bubble, and fluid flow effects. These trade-offs and the effect of different mixing regimes were theoretically analyzed to quantify how device design decisions impact performance. The results were found to concur with data from cell-free NMR experiments performed in 18 mS/cm conductivity medium. The results also guided the redesign of an NMR bioreactor in terms of relative radio frequency (rf) coil and sample dimensions and other factors. The design, which entails using chemostat mixing to shunt sample through a rf coil in ca. 0.4 s, provides adequate oxygenation for the 4-16% (v/v) cell suspensions examined. Gains realized include lower conductive losses, better magnetic field homogeneity, and the exclusion of gas bubbles from the sampling zone. These gains enable the acquistion of spectra from dilute (3-4% v/v) Saccharomyces cerevisiae chemostat cultures in 6.9 min with high resolution in both the orthophosphate and the beta-NTP regions. Samples with 16% (v/v) cells also yield useful spectra within 0.5-1.0 min.

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“…TSB and BHI contain 11% and 7% dextrose (α- d -glucose), respectively, by dry organic weight, while MHB provides 7% starch (amylose and amylopectin), which can be hydrolyzed by most staphylococci via α-amylase to generate free sugars for glycolysis [ 22 ]. LB contains no added dextrose or starches, and the yeast extract ingredient has been shown to contribute less than 100 µM fermentable sugar equivalents (nucleotides, sugar phosphates, or oligosaccharides), which substantially slow the growth of Escherichia coli and S. aureus once the sugars are depleted [ 23 , 24 , 25 ]. A few other notable differences in the media may influence staph metabolism.…”

Section: Introductionmentioning

confidence: 99%

Dependence of the Staphylococcal Volatilome Composition on Microbial Nutrition

Jenkins

Bean

2020

Metabolites

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In vitro cultivation of staphylococci is fundamental to both clinical and research microbiology, but few studies, to-date, have investigated how the differences in rich media can influence the volatilome of cultivated bacteria. The objective of this study was to determine the influence of rich media composition on the chemical characteristics of the volatilomes of Staphylococcus aureus and Staphylococcus epidermidis. S. aureus (ATCC 12600) and S. epidermidis (ATCC 12228) were cultured in triplicate in four rich complex media (brain heart infusion (BHI), lysogeny broth (LB), Mueller Hinton broth (MHB), and tryptic soy broth (TSB)), and the volatile metabolites produced by each culture were analyzed using headspace solid-phase microextraction combined with comprehensive two-dimensional gas chromatography—time-of-flight mass spectrometry (HS-SPME-GC×GC-TOFMS). When comparing the chemical compositions of the staph volatilomes by the presence versus absence of volatiles produced in each medium, we observed few differences. However, when the relative abundances of volatiles were included in the analyses, we observed that culturing staph in media containing free glucose (BHI and TSB) resulted in volatilomes dominated by acids and esters (67%). The low-glucose media (LB and MHB) produced ketones in greatest relative abundances, but the volatilome compositions in these two media were highly dissimilar. We conclude that the staphylococcal volatilome is strongly influenced by the nutritional composition of the growth medium, especially the availability of free glucose, which is much more evident when the relative abundances of the volatiles are analyzed, compared to the presence versus absence.

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NMR studies of a bacterial cell culture medium (LB Broth): cyclic nucleosides in yeast extracts

Cited by 5 publications

References 0 publications

In situ 31P nuclear magnetic resonance for observation of polyphosphate and catabolite responses of chemostat-cultivated Saccharomyces cerevisiae after alkalinization

In situ 31P nuclear magnetic resonance for observation of polyphosphate and catabolite responses of chemostat-cultivated Saccharomyces cerevisiae after alkalinization

Performance Trade-offs in In Situ Chemostat NMR

Dependence of the Staphylococcal Volatilome Composition on Microbial Nutrition

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