2 research outputs found
Enhanced Synthesis of Alkyl Galactopyranoside by <i>Thermotoga naphthophila</i> Ī²āGalactosidase Catalyzed Transglycosylation: Kinetic Insight of a Functionalized Ionic Liquid-Mediated System
Green
synthesis is of pivotal importance for environmental sustainability.
This work reports a novel approach to synthesize an array of alkyl
galactopyranosides using thermophilic Ī²-galactosidase from <i>Thermotoga naphthophila</i> RKU-10 (TN1577) as biocatalyst and
milk processing waste lactose as galactosyl donor. Ammoeng 102 (only
2.5% addition of total reaction volume), a functionalized ionic liquid
(IL) containing tetraaminum cation with C<sub>18</sub> acyl and oligoethylene
glycol, is identified as the most promising one from a variety of
structurally diverse ILs, affording a 2.37-fold increase in octyl
galactopyranoside yield compared to the buffer system. Up to 18.2
g L<sup>ā1</sup> octyl galactopyranoside could be produced
in 7 h, which is significantly higher than any previous report in
terms of time-space efficiency. Kinetic study and COSMO-RS <i>in silico</i> predictions elucidate that the thermophilic nature
of TN1577 Ī²-galactosidase, increased solubility of substrate,
suppression of hydrolysis, and excellent biocompatibility of Ammoeng
102 with enzyme (allowing TN1577 Ī²-galactosidase to perform
optimal catalysis up to 95 Ā°C) are the main driving forces. The
general applicability of the Ammoeng 102 system is verified, by which
a series of alkyl galactopyranosides are successfully synthesized
with <i>n</i>-butanol to <i>n</i>-tetradecanol
as alkyl acceptors and lactose as galactosyl donor
Valorizing Dairy Waste: Thermophilic Biosynthesis of a Novel Ascorbic Acid Derivative
l-Ascorbic acid (l-AA) is an essential nutrient that is extremely unstable and cannot
be synthesized by the human body. Therefore, attempts have been performed
to develop biologically active l-AA derivatives with improved
stability. This work presents a facile, scalable, and efficient enzymatic
transgalactosylation of lactose to l-AA using Ī²-glucosidase
(TN0602) from Thermotoga naphthophila RKU-10. Ī²-Glucosidase TN0602 displays high transgalactosylation
activity at pH 5.0, 75 Ā°C, and l-AA/lactose ratio of
2:1 to form a novel l-AA derivative [2-<i>O</i>-Ī²-d-galactopyranosyl-l-ascorbic acid (l-AA-Gal)] with a maximal productivity of 138.88 mmol L<sup>ā1</sup> in 12 h, which is higher than most reports of enzymatic
synthesis of l-AA-Ī±-glucoside. Synthetic l-AA-Gal retains most l-AA antioxidant capability and presents
dramatically higher stability than l-AA in an oxidative environment
(Cu<sup>2+</sup>). In conclusion, this work reports a new way to valorize
dairy waste lactose into a novel molecule l-AA-Gal, which
could be a promising l-AA derivative to be used in a wide
range of applications