New model development for qualitative and quantitative analysis of microbial polyhydroxyalkanoates: A comparison of Fourier Transform Infrared Spectroscopy with Gas Chromatography

Abstract : FT-IR spectroscopy is a non-destructive testing technique that requires minimal sample preparation time and allows the rapid characterization of structural features of complex, polymeric material. This technique has been frequently used in the past for the detection of PHA (Polyhydroxyalkanoates) but rarely for their quantification. In this work, by using cluster and discriminant statistical analysis of FT-IR data, different models are proposed for rapid identification of PHA monomers produced under different growth conditions by bacterial strains, and for their semi quantification. The results on the ability to produce large amounts of PHA (of 21 strains) in different environmental conditions of medium, substrates and deficiency of nutrients are presented. The spectral data analysis gives qualitative and semi quantitative information about the PHA produced in the samples. Models are proposed to test a large number of cultural conditions of strains and substrates in the field of screening and for identifying best conditions of PHA production in lab scale bioreactor and on industrial scale.