Low water systems have become important for organic synthetic reactions cat
alysed by enzymes. Esterification reactions could be catalysed by lipase in
multiphasic reaction media, such as foams, containing excess water. The es
terification of glycerol with oleic acid catalysed by lipase in aqueous foa
ms has been characterised. More than 80% of the oleic acid was converted to
glycerides within 10 h. Preliminary characterisation of the reaction with
respect to time, pH and temperature indicate that acylglycerol synthesis in
foam media as similar to hydrolysis by the same lipase. The observed high
K-m of glycerol for the esterification reaction may be due to poor surface
active properties of glycerol. The unique advantages of foam as a medium to
conduct lipase reactions are discussed. (C) 1999 Society of Chemical Indus
try.