Fourier Transform Infrared Spectroscopy for Screening and Quantifying Production of PHAs by Pseudomonas Grown on Sodium Octanoate

• Published in: Biomacromolecules 2003-07, Vol.4 (4), p.1092-1097
• Main Authors: Randriamahefa, Solo, Renard, Estelle, Guérin, Philippe, Langlois, Valérie
• Format: Article
• Language: English
• Subjects: Applied sciences; Bioconversions. Hemisynthesis; Biological and medical sciences; Biotechnology; Caprylates - metabolism; Exact sciences and technology; fourier transform infrared spectroscopy; Fundamental and applied biological sciences. Psychology; Hydroxybutyrates - analysis; Hydroxybutyrates - chemistry; Hydroxybutyrates - metabolism; Methods. Procedures. Technologies; Organic polymers; Physicochemistry of polymers; Polyesters - analysis; Polyesters - chemistry; Polyesters - metabolism; Polymerization; Preparation, kinetics, thermodynamics, mechanism and catalysts; Pseudomonas; Pseudomonas - chemistry; Pseudomonas - growth & development; Pseudomonas - metabolism; sodium octanoate; Spectroscopy, Fourier Transform Infrared - methods
• ISSN: 1525-7797; 1526-4602
• DOI: 10.1021/bm034104o

Poly(hydroxyalkanoates) PHAs are synthesized by many bacteria as inclusion bodies and their biodegradability and structural diversity have been studied with a view to their potential application as biodegradable materials. A method based on FT-IR was developed to carry out rapid qualitative and quantitative analysis of PHAs in Pseudomonas, when they were grown on sodium octanoate. Using absorbance of the ester band of PHAs, a rapid method was reported to distinguish PHB and PHO and to determine polymer content in intact bacteria. Relative areas in which the CO area was normalized to the area of the peak representing the amid group (1656 cm-1) characteristic of bacteria were calibrated to the polymer content which was determined after solvent extraction. Polymer contents vary from 0% to 53% and depend on the nature of the bacteria. Among 27 strains of Pseudomonas belonging to the rRNA homology group I, a very low amount of bacteria were able to produce PHB. The majority of strains were able to produce a copolymer, PHO, in which the major constituent unit is 3-hydroxyoctanoate. The FT-IR results were further confirmed by gas chromatography analysis after methanolysis of polymer, but FT-IR method requires less preparation of sample than gas chromatography and it is very useful for screening a large variety of Pseudomonas.