The eobiotic compound indican lends itself to a compelling biocatalytic dyeing strategy for denim, in which the formation of corrosive byproducts is avoided. However, the efficient and scalable production of indican remains a key bottleneck. This work focuses on the in vitro characterization of PtUGT1, a glycosyltransferase from Polygonum tinctorium that catalyzes the formation of indican via the glycosylation of indoxyl. Here, the buffer composition and enzyme concentration were identified as key parameters for enzyme activity and stability. The short lifetime of the enzyme under reaction conditions initiated an immobilization study. As a consequence, an amino-functionalized methacrylate resin was identified as a highly functional option for efficient immobilization of PtUGT1, allowing immobilization yields of >98% for enzyme loadings up to 7.6 wt %. We further report a stabilization factor of 47 and significantly improved overall biocatalytic productivity. The straightforward handling and reuse of the described heterogeneous biocatalyst is demonstrated.

The ongoing racial admixture was studied in the island of Itaparica off the coast of the State of Bahia, in Brazil. The following gene frequencies were observed: Hb S = 0.039; Hb C = 0.022; PGD C = 0.024; Gd A = 0.217 and Gd Ā = 0.052, among 293 mixed school children whose black phenotype index (medium mulatto + dark mulatto + black/total) was 0.457. Data on racial groups, obtained from 898 death certificates of three periods (1889–1890, 1934–1937 and 1975–1980) showed that in about 90 years (three generations) the proportion of mulattoes had doubled, the whites had decreased to one third, and the blacks showed no variation. Changes in the frequencies of surnames within the whites over the same 90 years indicated a growing proportion of individuals with black ancestry flowing into the white group. Higher reproductive rates among the more negroid individuals is probably the leading force directing the racial admixture in the island.

The eobiotic compound indican lends itself to a compelling biocatalytic dyeing strategy for denim, in which the formation of corrosive by-products is avoided. However, the efficient and scalable production of indican remains a key bottleneck. This work focuses on the in vitro characterization of PtUGT1, a glycosyltransferase from Polygonum tinctorium that catalyzes the formation of indican via the glycosylation of indoxyl. Here, the buffer composition and enzyme concentration were identified as key parameters for enzyme activity and stability. The short lifetime of the enzyme under reaction conditions initiated an immobilization study. As a consequence, an amino-functionalized methacrylate resin was identified as a highly functional option for efficient immobilization of PtUGT1, allowing immobilization yields of > 98% for enzyme loadings up to 7.6 w-%. We further report a stabilization factor of 47 and significantly improved overall biocatalytic productivity. The straightforward handling and reuse of the described heterogeneous biocatalyst is demonstrated.

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The eobiotic compound indican lends itself to a compelling biocatalytic dyeing strategy for denim, in which the formation of corrosive by-products is avoided. However, the efficient and scalable production of indican remains a key bottleneck. This work focuses on the in vitro characterization of PtUGT1, a glycosyltransferase from Polygonum tinctorium that catalyzes the formation of indican via the glycosylation of indoxyl. Here, the buffer composition and enzyme concentration were identified as key parameters for enzyme activity and stability. The short lifetime of the enzyme under reaction conditions initiated an immobilization study. As a consequence, an amino-functionalized methacrylate resin was identified as a highly functional option for efficient immobilization of PtUGT1, allowing immobilization yields of > 98% for enzyme loadings up to 7.6 w-%. We further report a stabilization factor of 47 and significantly improved overall biocatalytic productivity. The straightforward handling and reuse of the described heterogeneous biocatalyst is demonstrated.