Two-stage recovery of S-adenosylmethionine using supported liquid membranes with strip dispersion
•Two step supported liquid membranes with strip dispersion was investigated.•SAM was successfully separated from a fermentation broth.•MiniModule® module and the mixed extractants of AOT, DEHPA and TOPO were adopted.•SAM recovery efficiency 91.8%, Met removal efficiency 85.4% were gained within 5 h.•The mass transport kinetics was analyzed.
We report the selective recovery of S-adenosylmethionine (SAM) from fermentation broths using a two-stage supported liquid membrane system with strip dispersion (SLM-SD). The system utilized two MiniModule® hollow-fiber membrane modules as microporous supports and an organic membrane solution consisting of the extractants of sodium di-2-ethylhexyl sulfosuccinate (AOT), di-(2-ethylhexyl)phosphoric acid (DEHPA), and trioctylphosphine oxide (TOPO) in the solvent n-octanol. SAM was extracted in the first membrane module. Methionine (Met) was captured by the first stripping solution and further purified in the second membrane module. pH values in the feed phase and the first and second stripping solutions, extractant concentrations, NaCl concentration, and the SAM acceptor in the first stripping solution were optimized. Strip dispersion mixing speed, pressure differences across the membranes, and flow rates of the feed and strip dispersion phases were investigated experimentally. The optimal extractant concentrations were: AOT 2.78 wt%, DEHPA 27.0 wt%, and TOPO 1.61 wt%. The optimal pH values in the feed phase and the first and second stripping solution were 3.0, 2.5, and 1.0, respectively. SAM extraction efficiency of 98.7%, SAM recovery efficiency of 91.8% and Met removal efficiency of 85.4% were achieved within 5 h. Finally, the mass transfer analysis indicated that the mass transfer resistances from the extraction reaction and the membrane phase were predominant.
Journal: Process Biochemistry - Volume 48, Issue 12, December 2013, Pages 1980–1991