Yuxiang Tang,Wei Liu,Jiangling Wan,Yuanxin Wang,Xiangliang Yang
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.
Gel electrophoresis (GE) is one of the most general tools in biomedicine. However, it suffers from low resolution, and its mechanism has not been fully revealed yet. Herein, we presented the dispersion model of w2 (t) ∝ Tt, showing the band dispersion (w) via temperature (T) and running time (t) control. Second, we designed an efficient GE chip via the time control and rapid Joule heat self-dissipation by thermal conductive plastic (TCP) and electrode buffer. Third, we conducted the simulations on TCP and polymethylmethacrylate (PMMA) chips, unveiling that (i) the temperature of TCP was lower than the PMMA one, (ii) the temperature uniformity of TCP was better than the PMMA one, and (iii) the resolution of TCP was superior to the PMMA one. Fourth, we designed both TCP and PMMA chips for experimentally validating the dispersion model, TCP chip, and simulations. Finally, we applied the TCP chip to thalassemia and model urine protein assays. The TCP chip has merits of high resolution, rapid run of 6–10 min, and low cost. This work paves the way for greatly improving electrophoretic techniques in gel, chip, and capillary via temperature and time control for biologic study, biopharma quality control, clinical diagnosis, and so on.
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