College of Food Science and Engineering, Ocean University of China, Qingdao, 266003, People's Republic of China.
Marine Fisheries Research Institute of Zhejiang, Zhoushan, 316021, People's Republic of China.
Environ Sci Pollut Res Int. 2018 Feb;25(4):3745-3755. doi: 10.1007/s11356-017-0785-5. Epub 2017 Nov 22.
Pichia kudriavzevii YB5, mutated from Pichia kudriavzevii A16 with a strong ability to remove cadmium ions, was immobilized by polyurethane foam and alginate gels in this work. The immobilization conditions were optimized as follows: sodium alginate concentration of 2% (w/v), calcium chloride concentration of 2% (w/v), biomass dose of 1 × 10 cell/mL, and cross-linking time for 4 h. Then, the results of batch adsorption experiments showed that the removal capacity of prepared bioadsorbent was significantly affected by the pH of media, contact time, and the initial Cd(II) concentration, and a suitable adsorption conditions of Cd(II) could be achieved with a pH value of 6.0 at 20 °C for 90 min. Kinetic and isothermal results indicated the behavior of Cd(II) adsorption onto immobilized P. kudriavzevii YB5 fitted to the pseudo-second-order kinetic equation and the Langmuir adsorption model. Thermodynamic results showed that the Cd(II) adsorption process was endothermic and spontaneous in nature. Besides, the Cd(II) removing capacity of the prepared bioadsorbent was also tested in the oyster hydrolysates, showing an average removal rate of 54.35%. Thus, the immobilized P. kudriavzevii YB5 adsorbent had great potential for application in aquatic products to ensure the food safety.
毕赤酵母 YB5 经诱变后具有较强的镉离子去除能力，突变株来自毕赤酵母 A16。本工作利用聚氨酯泡沫和海藻酸钠凝胶对其进行固定化。优化了固定化条件：海藻酸钠浓度为 2%（w/v），氯化钙浓度为 2%（w/v），生物量剂量为 1×10 细胞/mL，交联时间为 4 h。然后，批吸附实验结果表明，制备的生物吸附剂的去除能力受介质 pH 值、接触时间和初始 Cd(II)浓度的显著影响，在 20°C 时，pH 值为 6.0，吸附 90 min 可达到适宜的 Cd(II)吸附条件。动力学和等温线结果表明，Cd(II)吸附到固定化毕赤酵母 YB5 的行为符合准二级动力学方程和 Langmuir 吸附模型。热力学结果表明，Cd(II)吸附过程本质上是吸热和自发的。此外，还在牡蛎水解物中测试了制备的生物吸附剂的 Cd(II)去除能力，平均去除率为 54.35%。因此，固定化毕赤酵母 YB5 吸附剂在水产养殖中具有很大的应用潜力，可确保食品安全。
