Fig. 2.

Enzymatic butyl butyrate synthesis. a, b Five repeated 24 h reactions catalyzed by Lipase M entrapped in calcium alginate alone or with CLPs, c-CLPs, SKL, water-soluble cationic lignin (Catlig), Tween 80, DDMA, or sodium dodecyl sulfate (SDS). c A structure model of cationic lignin²⁴. d Relative synthetic activity (the ratio of synthetic activity in hexane-water 1:9 v/v to the activity detected in hexane-water 1:1 v/v) of immobilized hydrolases. The reaction conditions in a, b and d were similar (40 °C, pH 3, 200 rpm agitation). Error bars represent two standard deviations from the mean values (two replicates on a single batch of biocatalyst, except for c-CLP in a six replicates (three biocatalyst batches) for the first reaction, and four replicates (two biocatalyst batches) for the reactions 2‒5). Asterisks in d indicate statistically significant differences (p < 0.05, one-way ANOVA with Tukey’s HSD test). Details of ANOVA associated with a, b are given in Supplementary Table 5