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Isotopic composition of inorganic carbon as an indicator of benzoate degradation by Pseudomonas putida: temperature, growth rate and pH effects
Author(s) -
Barth Johannes A. C.,
Kalin Robert M.,
Larkin Mike J.,
Hall James A.,
Fitzgerald Una
Publication year - 2000
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/1097-0231(20000815)14:15<1316::aid-rcm933>3.0.co;2-4
Subject(s) - chemistry , pseudomonas putida , carbon fibers , isotopes of carbon , stable isotope ratio , composition (language) , kinetic isotope effect , environmental chemistry , analytical chemistry (journal) , total organic carbon , organic chemistry , linguistics , materials science , physics , philosophy , deuterium , quantum mechanics , composite number , composite material , enzyme
Degradation experiments of benzoate by Pseudomonas putida resulted in enzymatic carbon isotope fractionations. However, isotopic temperature effects between experiments at 20 and 30 °C were minor. Averages of the last three values of the CO 2 isotopic composition (δ 13 C CO2(g) ) were more negative than the initial benzoate δ 13 C value (−26.2‰ Vienna Pee Dee Belenite (VPDB)) by 3.8, 3.4 and 3.2‰ at 20, 25 and 30 °C, respectively. Although the maximum isotopic temperature difference found was only 0.6‰, more extreme temperature variations may cause larger isotope effects. In order to understand the isotope effects on the total inorganic carbon (TIC), a better measure is to calculate the proportions of the inorganic carbon species (CO 2 (g), CO 2 (aq) and HCO 3 − ) and to determine their cumulative δ 13 C TIC . In all three experiments δ 13 C TIC was more positive than the initial isotopic composition of the benzoate at a pH of 7. This suggests an uptake of 12 C in the biomass in order to match the carbon balance of these closed system experiments. Copyright © 2000 John Wiley & Sons, Ltd.