title: Measurement of protein biomass by Fourier transform infrared-photoacoustic spectroscopy.
abstract: A relatively new analytical technique, Fourier transform infrared-photoacoustic spectroscopy (FTIR-PAS), provides spectra of bacteria, fungi, and other microorganisms in solid states not suitable for conventional absorption spectroscopy. In this paper the feasibility of quantitative measurement of protein biomass on solid substrates by FTIR-PAS is examined and discussed. By measuring photoacoustic absorption bands from amide groups in the protein of microorganisms, the increase in biomass that occurs during growth was monitored directly and accurately. Incorporation of polyacrylonitrile into the sample as an internal standard was shown to be a convenient method for improving both the reliability and the range of detection by photoacoustic spectroscopy. Results of FTIR-PAS measurements of known quantities of microbial mass in simulated growth experiments suggest that the technique may be especially suitable for assays of microorganisms used in solid-state biosyntheses of drugs, hormones, and other biological agents.
authors.affiliation: United States Department of Agriculture, Northern Regional Research Center, Peoria, Illinois 61604.
authors.forename: S H
authors.initials: SH
authors.lastname: Gordon
authors.forename: R V
authors.initials: RV
authors.lastname: Greene
authors.forename: S N
authors.initials: SN
authors.lastname: Freer
authors.forename: C
authors.initials: C
authors.lastname: James
mesh_terms: D000162:Acoustics; D001426:Bacterial Proteins / Q000032:analysis*; D004926:Escherichia coli / Q000254:growth & development; D005583:Fourier Analysis; D005656:Fungal Proteins / Q000032:analysis*; D005658:Fungi / Q000254:growth & development; D008855:Microscopy, Electron, Scanning; D012441:Saccharomyces cerevisiae / Q000254:growth & development; D013055:Spectrophotometry, Infrared
chemical_list: D001426:Bacterial Proteins; D005656:Fungal Proteins