Not wild type--most strains don't use just glutamate. We'll be growing on 13-C label, but don't want any confusion from heating etc. because we'll be measuring intramolecular patterns. Marilyn On Tue, Jun 8, 2021 at 3:50 PM Patrick Griffin <[log in to unmask]> wrote: > I’m curious about the study. E. coli (wild type) can be grown using any > single amino acid as the sole carbon source. Are you feeding with labeled > glutamic acid? It’s hard to say that with a straight face since the number > of mutant E. coli strains is huge and I don’t know the metabolic properties > of the specific strain. I’m sure there’s even variety within the STEC > family of strains. > > I ask because, if you mean you want to measure d2H of glutamic acid, there > is a technical hitch. Hot acid hydrolysis followed by derivatization > essentially mixes glutamine with glutamic acid. > > Is it known that five minutes of boiling kills the bugs and denatures the > stx? Maybe I’m a coward, but I’d boil it a longer. > > On Mon, Jun 7, 2021 at 7:24 PM Marilyn Fogel <[log in to unmask]> > wrote: > >> https://link.springer.com/article/10.1007/s00442-020-04730-9 >> >> and >> >> https://www.pnas.org/content/113/32/E4648.short >> >> We've published H in amino acids in these two papers--and have several >> more manuscripts ready for submission. It works very well. >> >> To get back to this, the E. coli strain that uses glutamate (our target >> AA) needs a BSL2 safety cabinet. It needs to be killed before removing from >> the cabinet since it produces toxins. >> >> We'll process it as usual once dead. >> >> Marilyn >> >> >> >> Marilyn L. Fogel >> Distinguished Emerita Professor of Geoecology >> Dept. of Earth and Planetary Sciences >> University of California Riverside >> Riverside, CA, USA >> https://isotopequeen.blogspot.com/ >> >> >> >> On Mon, Jun 7, 2021 at 3:56 AM Fred Martin Kaaby <[log in to unmask]> >> wrote: >> >>> I think altering the pH or osmotic pressure (salt) would "pop" most >>> bacterias just as well as heating. >>> >>> Just a non-related question. How do you analyze specific amino acids for >>> C and H? >>> Since I am looking into capillary electrophoresis it easily comes into >>> mind here, have someone tried CE-IRMS for the analysis of amino acids, >>> proteins etc? >>> >>> Fred >>> >>> -----Original Message----- >>> From: Stable Isotope Geochemistry <[log in to unmask]> On Behalf >>> Of Tabor, Neil >>> Sent: søndag 6. juni 2021 18:59 >>> To: [log in to unmask] >>> Subject: Re: [ISOGEOCHEM] effect of "heat killing"? >>> >>> Or Hg(II)? >>> >>> On 6/6/21, 11:24 AM, "Stable Isotope Geochemistry on behalf of Max >>> Coleman" <[log in to unmask] on behalf of [log in to unmask]> >>> wrote: >>> >>> [EXTERNAL SENDER] >>> >>> Marilyn >>> >>> If the need is to just to kill them, why not use an old fashioned >>> metal ion bactericide, e.g. Ag, Cu or Zn? >>> >>> Good luck >>> >>> Max >>> >>> –------------------------------- >>> Max Coleman >>> Senior Research Scientist >>> NASA Jet Propulsion Lab, Caltech >>> +1 818 393 6353, cell: +1 818 687 7704 >>> [log in to unmask] >>> –------------------------------- >>> >>> > On 5 Jun 2021, at 14:25, Marilyn Fogel <[log in to unmask]> >>> wrote: >>> > >>> > Colleagues, >>> > >>> > We're doing an experiment with a toxic strain of E. coli. In order >>> to simplify processing the sample, I've been asked if boiling at 100°C for >>> 5 minutes would alter isotope signals. >>> > >>> > We're analyzing compound specific amino acids for C and H. I'm >>> hesitant to try this, somehow. >>> > >>> > Any experience? Your thoughts? >>> > >>> > Marilyn Fogel >>> >>>