title: Rapid total volatile organic carbon quantification from microbial fermentation using a platinum catalyst and proton transfer reaction-mass spectrometry.
abstract: A novel analytical system was developed to rapidly and accurately quantify total volatile organic compound (VOC) production from microbial reactor systems using a platinum catalyst and a sensitive CO2detector. This system allows nearly instantaneous determination of total VOC production by utilizing a platinum catalyst to completely and quantitatively oxidize headspace VOCs to CO2in coordination with a CO2detector. Measurement of respiratory CO2by bypassing the catalyst allowed the total VOC content to be determined from the difference in the two signals. To the best of our knowledge, this is the first instance of a platinum catalyst and CO2detector being used to quantify the total VOCs produced by a complex bioreactor system. Continuous recording of these CO2data provided a record of respiration and total VOC production throughout the experiments. Proton transfer reaction-mass spectrometry (PTR-MS) was used to identify and quantify major VOCs. The sum of the individual compounds measured by PTR-MS can be compared to the total VOCs quantified by the platinum catalyst to identify potential differences in detection, identification and calibration. PTR-MS measurements accounted on average for 94 % of the total VOC carbon detected by the platinum catalyst and CO2detector. In a model system, a VOC producing endophytic fungus Nodulisporium isolate TI-13 was grown in a solid state reactor utilizing the agricultural byproduct beet pulp as a substrate. Temporal changes in production of major volatile compounds (ethanol, methanol, acetaldehyde, terpenes, and terpenoids) were quantified by PTR-MS and compared to the total VOC measurements taken with the platinum catalyst and CO2detector. This analytical system provided fast, consistent data for evaluating VOC production in the nonhomogeneous solid state reactor system.
authors.affiliation: Department of Chemical & Biological Engineering, Montana State University, 305 Cobleigh Hall, PO Box 173920, Bozeman, MT, 59717, USA.|Center for Biofilm Engineering, Montana State University, 366 Barnard Hall, P.O. Box 173980, Bozeman, MT, 59717, USA.
authors.forename: Heidi R
authors.initials: HR
authors.lastname: Schoen
authors.affiliation: Department of Chemical & Biological Engineering, Montana State University, 305 Cobleigh Hall, PO Box 173920, Bozeman, MT, 59717, USA.|Center for Biofilm Engineering, Montana State University, 366 Barnard Hall, P.O. Box 173980, Bozeman, MT, 59717, USA.
authors.forename: Brent M
authors.initials: BM
authors.lastname: Peyton
authors.affiliation: Department of Chemistry and Biochemistry, Montana State University, 103 Chemistry and Biochemistry Building, PO Box 173400, Bozeman, MT, 59717, USA. bknighton@chemistry.montana.edu.
authors.forename: W Berk
authors.initials: WB
authors.lastname: Knighton
keywords: Fungal endophyte; Proton transfer reaction-mass spectrometry; Solid state fermentation; Total volatile organic carbon