Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!pasteur!agate!violet.berkeley.edu!dean
From: dean@violet.berkeley.edu (Dean Pentcheff)
Newsgroups: sci.bio
Subject: Re: Metabolic selection of isotopes?
Message-ID: <7570@agate.BERKELEY.EDU>
Date: 10 Mar 88 04:19:45 GMT
References: <3230@zeus.TEK.COM>
Sender: usenet@agate.BERKELEY.EDU
Reply-To: dean@violet.berkeley.edu.UUCP (Dean Pentcheff)
Followup-To: sci.bio
Organization: University of California, Berkeley   Department of Zoology
Lines: 22
Summary: Not unique behavior

In article <3230@zeus.TEK.COM> dant@mrloog.LA.TEK.COM (Dan Tilque) writes:
>	... carbon-13.  He
>	suggested that the bacteria, which feed on organic molecules, have
>	a metabolism that selects this heavy isotope when producing carbon
>	dioxide."
>I have never heard of any metabolic process which could distinguish
>isotopes.  Is this bacteria unique or are there other cases like it?

No, this is standard behavior.  For example, when oceanographers use
the isotope C-14 for measuring photosynthetic rate they apply a standard
correction factor to compensate for differential uptake of C-14 and C-12
by phytoplankton.

Can anyone shed some light on the chemical mechanisms that are involved?

-Dean


-----------------
Dean Pentcheff	(dean@violet.berkeley.edu)
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"A university is a place where people pay high prices for goods which they then
proceed to leave on the counter when they go out of the store."  Loren Eiseley