FORMATION OF BENZALDEHYDE BY PSEUDOMONAS-PUTIDA ATCC-12633

Aromatic and heterocyclic aldehydes may be produced by the mandelate p athway of Pseudomonas putida ATCC 12633 via the biotransformation of b enzoyl formate and substrate analogues. Under optimised biotransformat ion conditions (37 degrees C, pH 5.4) and with benzoyl formate as a su bstrate, benzaldehyde may be accumulated with yields above 85%. Benzal dehyde is toxic to P. putida ATCC 12633; levels above 0.5 g/l (5 mM) r educe the biotransformation activity. Total activity loss occurs at an aldehyde concentration of 2.1 g/l (20 mM). To overcome this limitatio n, the rapid removal of the aldehyde is desirable via in situ product removal. The biotransformation of benzoyl formate (working volume 1 l) without in situ product removal accumulates 2.1 g/l benzaldehyde. Ben zaldehyde removal by gas stripping produces a total of 3.5 g/l before inhibition. However, the most efficient method is solid-phase adsorpti on using activated charcoal as the sorbant, this allows the production of over 4.1 g/l benzaldehyde. Addition of bisulphite as a complexing agent causes inhibition of the biotransformation and bisulphite is the refore is not suitable for in situ product removal.