title: Influence of physical and chemical properties of HTSXT-FTIR samples on the quality of prediction models developed to determine absolute concentrations of total proteins, carbohydrates and triglycerides: a preliminary study on the determination of their absolute concentrations in fresh microalgal biomass.
abstract: Absolute concentrations of total macromolecules (triglycerides, proteins and carbohydrates) in microorganisms can be rapidly measured by FTIR spectroscopy, but caution is needed to avoid non-specific experimental bias. Here, we assess the limits within which this approach can be used on model solutions of macromolecules of interest. We used the Bruker HTSXT-FTIR system. Our results show that the solid deposits obtained after the sampling procedure present physical and chemical properties that influence the quality of the absolute concentration prediction models (univariate and multivariate). The accuracy of the models was degraded by a factor of 2 or 3 outside the recommended concentration interval of 0.5-35 µg spot(-1). Change occurred notably in the sample hydrogen bond network, which could, however, be controlled using an internal probe (pseudohalide anion). We also demonstrate that for aqueous solutions, accurate prediction of total carbohydrate quantities (in glucose equivalent) could not be made unless a constant amount of protein was added to the model solution (BSA). The results of the prediction model for more complex solutions, here with two components: glucose and BSA, were very encouraging, suggesting that this FTIR approach could be used as a rapid quantification method for mixtures of molecules of interest, provided the limits of use of the HTSXT-FTIR method are precisely known and respected. This last finding opens the way to direct quantification of total molecules of interest in more complex matrices.
authors.affiliation: Université de Nantes, GEPEA UMR CNRS 6144, Bât. CRTT, 37 bd de l'Université, BP 406, 44602, Saint-Nazaire Cedex, France.
authors.forename: Esteban
authors.initials: E
authors.lastname: Serrano León
authors.forename: Rémy
authors.initials: R
authors.lastname: Coat
authors.forename: Benjamin
authors.initials: B
authors.lastname: Moutel
authors.forename: Jérémy
authors.initials: J
authors.lastname: Pruvost
authors.forename: Jack
authors.initials: J
authors.lastname: Legrand
authors.forename: Olivier
authors.initials: O
authors.lastname: Gonçalves
mesh_terms: D020418:Algal Proteins / Q000032:analysis; D018533:Biomass; D001709:Biotechnology; D002241:Carbohydrates / Q000032:analysis; D057166:High-Throughput Screening Assays / Q000379:methods* / Q000706:statistics & numerical data; D016018:Least-Squares Analysis; D016014:Linear Models; D058086:Microalgae / Q000737:chemistry* / Q000254:growth & development; D015999:Multivariate Analysis; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods* / Q000706:statistics & numerical data; D014280:Triglycerides / Q000032:analysis
chemical_list: D020418:Algal Proteins; D002241:Carbohydrates; D014280:Triglycerides