Metabolism of phenylalanine and biosynthesis of styrene in Penicillium camemberti.
The occurrence of styrene in food may be an important aroma defect (celluloid odour), even at very low concentrations (Miltz et al. 1980) causing consumer rejection and is therefore a problem for the food industry. We examined the biosynthetic pathway leading to styrene formation by Penicillium camemberti using labelled compounds. As styrene is strongly hydrophobic and volatile, we first had to develop a continuous extraction process. Using resins XAD2 it was reasonable to suspect phenylalanine (Phe) as the precursor. The addition of Phe marked with 13C on the ring provokes the accumulation of labelled styrene. The enzyme activities involved were also tentatively measured. Styrene appears to be synthesized from phenylalanine by phenylalanine ammonia-lyase activity followed by a decarboxylation catalysed by a cinnamic acid decarboxylase.
Pagot
Yves
Y
UMR de Microbiologie et Génétique Moléculaire, Institut National Agronomique Paris-Grignon, UMR INRA 537, URA CNRS 1925, F-78850 Thiverval-Grignon France. pagot@grignon.inra.fr
Belin
Jean-Marc
JM
Husson
Florence
F
Spinnler
Henry-Eric
HE
D005516:Food Microbiology; D008401:Gas Chromatography-Mass Spectrometry; D009812:Odorants; D010407:Penicillium / Q000201:enzymology / Q000378:metabolism*; D010649:Phenylalanine / Q000378:metabolism*; D010650:Phenylalanine Ammonia-Lyase / Q000378:metabolism; D020058:Styrene / Q000378:metabolism*
D020058:Styrene; D010649:Phenylalanine; D010650:Phenylalanine Ammonia-Lyase