Alston_2002_Biotechnol.Bioeng_77_641

Reference

Title : A comparison of lipase-catalysed ester and lactone synthesis in low-water systems: analysis of optimum water activity - Alston_2002_Biotechnol.Bioeng_77_641
Author(s) : Alston MJ , Freedman RB
Ref : Biotechnol Bioeng , 77 :641 , 2002
Abstract :

We investigated the effects of the lyophilisation medium (enzyme plus buffer salt and additives) and of water activity (a(w)) on the catalytic properties of lipase from Chromobacterium viscosum (lipase CV) in organic solvents; catalysis of ester and lactone synthesis were compared and, despite the similarities of the reactive groups involved in these reactions, some interesting differences were observed. Including 2-[N-morpholino]ethanesulfonic acid (MES) buffer in the lyophilisation medium of lipase CV increased its catalytic activity in transesterification and lactonisation, although the buffer salt requirement for maximal activity differed between the two reactions. Sorbitol, glucose, lactose, 18-crown-6 (crown ether 18-C-6), beta-cyclodextrin and bovine serum albumin were employed as alternative additives in the transesterification reaction, but were not as effective as MES buffer. Salt hydrates were used to investigate the effect of a(w) on esterification and lactonisation reactions catalysed by lipase CV. The maximum rate of hexadecanolide synthesis in toluene occurred at a(w) = 0.48. The optimum a(w) for the transesterification reaction in heptane/alcohol mixtures depended on the alcohol substrate employed (1-heptanol, 2-heptanol, or 3-methyl-3-hexanol) but not on the acyl donor (p-NP acetate or caprylate). The optimum a(w) values for both reactions were unchanged when a common solvent system (toluene/1-heptanol) was employed, indicating that the dependence of enzyme activity on a(w) is an intrinsic property of the enzyme-catalysed reaction and not a function of the solvent or other additives.

PubMedSearch : Alston_2002_Biotechnol.Bioeng_77_641
PubMedID: 11807759
Gene_locus related to this paper: burgl-lipas

Related information

Substrate Hexadecalactone
Gene_locus burgl-lipas

Citations formats

Alston MJ, Freedman RB (2002)
A comparison of lipase-catalysed ester and lactone synthesis in low-water systems: analysis of optimum water activity
Biotechnol Bioeng 77 :641

Alston MJ, Freedman RB (2002)
Biotechnol Bioeng 77 :641