Specificity of a Lipase in Ester Synthesis: Effect of Alcohol

Abstract

Ester synthesis by the Mucor miehei lipase has been studied for various alcohol substrates: n‐propanol, n‐butanol, isoamyl alcohol, n‐hexanol, n‐octanol, 2‐ethylhex‐anol, n‐decanol, and lauryl alcohol. The effects of temperature, the nature of the acid, and immobilization of the lipase on its substrate specficity have been elucidated by carrying out esterifications at 29 and 50 °C with lauric and oleic acids and by using both the soluble and immobilized (resin‐adsorbed) forms of the lipase as catalysts. Higher synthesis rates were obtained with oleic acid than with lauric acid. A bimodal distribution pattern was observed for the reaction rate as a function of alcohol chain length. Two superimposed “bells” were obtained with maxima at C4 (butanol) and C10 (decanol) at 29 °C. Whereas immobilization of the lipase did not influence this substrate specificity, an increase in temperature to 50 °C caused a shift in the first peak from C4 to C6 (hexanol), while the second peak position was not affected. The minimum, in all cases, was found to be at C8 (octanol).

Immobilization of Lipases on Magnetic Collagen Fibers and Its Applications for Short-Chain Ester Synthesis

“…This is probably due to progressively higher steric hindrance by the methyl groups in the proximity of the hydroxyl group. Results consistent with our work have been observed in previous studies focusing on the effects of the structures of alcohols on ester synthesis catalyzed by lipases [39][40][41]. In general, Fe 3 O 4 -collagen immoblilzed lipases displayed high activity and specificity for butyrate synthesis in an n-hexane medium.…”

Biocatalysis using lipase encapsulated in microemulsion-based organogels in supercritical carbon dioxide

“…Similar observations have been made in other studies on the effect of alcohol chain length on lipase activity. Sawant and co-workers stated a maximum in the initial rate for 1-butanol for both immobilized M. miehei lipase [53] as well as for soluble Lipolase 100 L in a biphasic reaction system [54]. In addition, Delimitsou et al [24] reported the same finding for M. miehei lipase immobilized on HPMC-containing AOT MBG at 25 • C.…”

Production of flavor esters catalyzed by lipase B from Candida antarctica immobilized on magnetic nanoparticles

“…Other authors (Abbas et al, 2003;Gandhi et al, 2008;Sun et al, 2009) reported that the methanol molecules are able to bind to the to the active sites of the enzyme, limiting the amount of energy released and consequently preventing the enzyme from changing its conformation to the desired catalytic form. In other words, the enzyme might be partially inhibited in the presence of methanol (Sun et al, 2009).Alcohols have the property of binding to proteins and induce their dehydration, resulting in a drastic loss of enzymatic activity.…”