Primary recovery of thermostable lipase 42 derived from recombinant Escherichia coli BL21 in aqueous two-phase flotation

• We examine APTF system to purify intracellular lipase from recombinant Escherichia coli.
• Parameters influenced ATPF partitioning behavior were investigated.
• PEG/sodium citrate based ATPF successfully purified lipase under optimum condition.

An aqueous two-phase flotation (ATPF) composed of polyethylene glycol (PEG) and sodium citrate was constructed for direct purification of thermostable lipase 42 from recombinant Escherichia coli BL21(DE3) pLysS. The influences of varying phase forming composition, tie-line length (TLL), volume ratio (VR), crude loading (CL), system pH, gas nitrogen flow rate (FR) and flotation time (Ft) upon ATPF partitioning performance were investigated. The optimum purification condition of lipase was achieved at PEG 8000/sodium citrate ATPF comprising TLL of 25.4, VR of 0.3, CL of 20% (w/w) at pH 7 with average Ft of 10 min and FR at 20 mL/min. Lipase was successfully purified using ATPF up to 4.05-fold with a separation efficiency of 99%. Result of this study also demonstrated that recovery yield of lipase in PEG phase of up to 96% was achieved. These results reveal the potential of ATPF partitioning in recovery and purification of recombinant lipase.

Optimum conditions: 8000 molecular mass of PEG, 25.4% of TLL, pH 7, volume ratio of 0.3, 20% (w/w) of crude extract, 20 mL/min of nitrogen flow rate at 10 min flotation time.Figure optionsDownload as PowerPoint slide