Abstract Aqueous two-phase systems have been widely studied for the separation and recovery of bioproducts. In this study, the thermosensitive polymer EO30PO70 and pH-responsive polymers (PADB4.66 and PADB6.26) were used to develop a recyclable aqueous two-phase system suitable for spiramycin partitioning. EO30PO70 represents poly-(ethylene oxide-propylene oxide), where 30 and 70 indicate the proportions of ethylene oxide and propylene oxide, respectively. PADB4.66 and PADB6.26 represent poly-(acrylic acid-dimethylamine ethyl methacrylate-butyl methacrylate), where the numbers (4.66 and 6.26) in the subscripts indicate the isoelectric point of the polymers. The phase separation mechanism of ATPS was studied through low-field nuclear magnetic resonance (LF-NMR) and surface tension. Moreover, the parameters affecting spiramycin partitioning, such as system components and composition, pH, temperature, and type and concentration of additive salt, were investigated. The best partitioning conditions were determined using 4.70% PADB6.26 and 31.67% EO30PO70 in the presence of 0.05 mol/L NaSCN at 35 °C and pH = 9.2. The highest partition coefficient of spiramycin from fermentation broth was 11.92, with an extraction recovery of 97.69%. In addition, phase-forming polymers PADB6.26 and EO30PO70 could be recovered by regulating the pH or temperature, and their recoveries reached 92.39% and 98.76%, respectively.

中文翻译：

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基于 pH 响应和热敏聚合物的可回收水性两相系统中螺旋霉素的分配

摘要 水相两相系统已被广泛研究用于生物产品的分离和回收。在本研究中，热敏聚合物 EO30PO70 和 pH 响应聚合物（PADB4.66 和 PADB6.26）用于开发适用于螺旋霉素分配的可回收水性两相系统。EO30PO70代表聚(环氧乙烷-环氧丙烷)，其中30和70分别表示环氧乙烷和环氧丙烷的比例。PADB4.66和PADB6.26代表聚-(丙烯酸-二甲胺甲基丙烯酸乙酯-甲基丙烯酸丁酯)，其中下标中的数字(4.66和6.26)表示聚合物的等电点。通过低场核磁共振（LF-NMR）和表面张力研究了ATPS的相分离机制。此外，影响螺旋霉素分配的参数，对系统组分和组成、pH、温度以及添加剂盐的类型和浓度等进行了研究。在 0.05 mol/L NaSCN 存在下，在 35 °C 和 pH = 9.2 下，使用 4.70% PADB6.26 和 31.67% EO30PO70 确定最佳分配条件。发酵液中螺旋霉素的最高分配系数为11.92，提取回收率为97.69%。此外，通过调节pH或温度可以回收成相聚合物PADB6.26和EO30PO70，回收率分别达到92.39%和98.76%。发酵液中螺旋霉素的最高分配系数为11.92，提取回收率为97.69%。此外，通过调节pH或温度可以回收成相聚合物PADB6.26和EO30PO70，回收率分别达到92.39%和98.76%。发酵液中螺旋霉素的最高分配系数为11.92，提取回收率为97.69%。此外，通过调节pH或温度可以回收成相聚合物PADB6.26和EO30PO70，回收率分别达到92.39%和98.76%。