Supercritical carbon dioxide biocatalysis as a novel and green methodology for the enzymatic acylation of fibrous cellulose in one step

Aliphatic esters of cellulose have recently raised the interest on the field of biopolymers. The objective of this work is to develop a methodology for the enzymatic acylation of cellulose with long chain fatty groups in one step. Therefore we designed a system at which fibrous cellulose was enzymatically acylated with vinyl laurate in supercritical carbon dioxide (scCO2) and as a result cellulose laurate was formed. The biocatalysts used for this reaction were immobilized lipase Candida antarctica, immobilized esterase from hog liver and the immobilized cutinase Fusarium solani. The ester content of the product varied on the specificity of the biocatalyst used, reaching a maximum of 4.1% after 9 h of reaction. In our knowledge, it is the first time where fibrous cellulose is enzymatically acylated by a long chain aliphatic group in one step, without the necessity of any pretreatment.

► Fibrous cellulose was enzymatically acylated in one step without any pretreatment.
► scCO2 was used (i) as swelling factor for cellulose and (ii) as reaction medium.
► Vigorous agitation is essential for both cellulose swelling and enzymatic acylation.
► The highest ester content of the formed cellulose laurate was 4.1%.