Detection and Quantification of PHA

Gas chromatography (GC) analysis involving simultaneous solvent extraction and hydrolytic esterification of PHA is generally carried out for the determination of intracellular PHA content (Braunegg et al. 1978). GC analysis with propanoly-sis in hydrochloric acid rather than acidic methanolysis in sulfuric acid was also reported (Riis and Mai 1988). 

Quantification of microbial PHA using GC method is rapid, sensitive, reproducible, and requires only small amount of samples (5-10 mg) for the analysis. Other techniques of analysis such as IR spectrometry at 5.75 A (Juttner et al. 1975), two-dimensional fluorescence spectroscopy, flow cytometry (Degelau et al. 1995) HPLC (Karr et al. 1983), ionic chromatography, and enzymatic determination (Hesselmann et al. 1999) were also desalbed. For online determination of PHA content in recombinant E. coli system, Fourier transform mid-infrared spectrometry (FTIR) and microcalorimetric technique (Ruan et al. 2007 Jarute et al. 2004) were also reported. For precise composition determination and structural elucidation of PHA, a variety of nuclear magnetic resonance (NMR) spectroscopy techniques have also been applied and the most commonly used are proton ( H) and carbon-13 ( C) NMR (Doi et al. 1986 Jacob et al. 1986). 

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