A green and sustainable approach to utilize bio-ionic liquids for the selective precipitation of high purity agarose from an agarophyte extract

A few choline based bio-ionic liquids (bio-ILs) were employed for the first time for the selective precipitation of agarose from the hot seaweed extract of Gracilaria dura (an agarophyte) under ambient conditions. The method thus developed is much greener and economical in comparison with the methods widely practiced for agarose production. Among the bio-ILs, choline laurate was found to be the most effective for the isolation of agarose with a lower usage level (4.0%, w/w) with the yield of 14.0 +/- 0.5% w/w. Agarose obtained by this process had the desired properties required for molecular biological applications and gel electrophoresis. Furthermore the bio-ILs were recycled and reused for subsequent batches of agarose isolation without compromising the yield and quality of biopolymers.