. Conclusions
In this study, we report the enhancement of enzymatic cell wall
disruption of
C. protothecoides
using thermoresponsive polymers of
pNIPAM and p(NIPAM-co-AA) for lipid and reducing sugar recovery.
Results indicate that polymers were also able to disrupt microalgal cell
walls for lipid extraction without enzymes, but unable to hydrolyze
cell walls. With the presence of pNcAA-10, 68% and 33% cell disruption
can be achieved with and without enzyme, respectively, resulting in re-
spective lipid and reducing sugar yields of 59% and 50% (g/g, reducing
sugar/dry algal cell wall). The use of polymers in addition to enzymes
results in faster cell disruption with higher breakdown efficiency for im-proved lipid yield. The polymer was shown to function by i) stressing
and disrupting the cell wall to improve the susceptibility to enzyme
cleavage and ii) protecting the enzyme from denaturation. The use of
thermoresponsive polymers provides a simple and energy-efficient
approach to recovering biofuels and bioproducts from microalga.
Importantly, the polymer can readily be recovered and reused, thereby
reducing overall material costs