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China Surfactant Detergent & Cosmetics ›› 2021, Vol. 51 ›› Issue (11): 1045-1051.doi: 10.3969/j.issn.1001-1803.2021.11.002

• Basic research • Previous Articles     Next Articles

Removal of residual hydrogen peroxide after bleaching by microspheres containing catalase

Chen Jialin,Liu Gang,Sun Mengmeng,Guo Ting,Meng Tao()   

  1. School of Life Sciences and Engineering, South West Jiaotong University, Chengdu, Sichuan 610031, China
  • Received:2021-02-13 Revised:2021-09-22 Online:2021-11-22 Published:2021-11-19
  • Contact: Tao Meng E-mail:taomeng@swjtu.edu.cn

Abstract:

Calcium carbonate microspheres containing catalase were prepared by the method of bionic mineralization. The size and pore size of the enzyme-carrying microspheres were measured; the encapsulation efficiency, loading capacity and stability of the enzyme-carrying microspheres in harsh environments were studied; the removal of residual hydrogen peroxide from the gauze after bleaching was studied. The results show that the enzyme-carrying microspheres have a particle size of approximately 11 μm. From the nitrogen adsorption-desorption isotherm and pore size distribution diagram, it can be seen that CAT@CaCO3 microspheres have uniformly distributed pores (approximately 5.53 nm), which can well encapsulate catalase (approximately diameter 6 nm×10 nm), allowing the substrate H2O2 and the product H2O to diffuse freely. Under the condition that the mass concentration of catalase is 0.15 mg/mL, the microsphere has a maximum load of 24.26 mg/g for catalase. Meanwhile, the enzyme encapsulation rate is 98%, and the enzyme activity retention rate is 72%, indicative of the mildness of the method of enzyme immobilization. Compared with free enzymes, the enzyme-carrying microspheres have improved thermal stability (38.99% of relative enzyme activity can still be retained at 80 ℃) and have changed the trend of catalase tolerance to different pH environments (the optimal pH for the enzyme activity shifts from pH 8 to pH 11). This phenomenon may be ascribedto the mineralization and fixation of calcium carbonate changing the conformation of the enzyme. To a certain extent, the conformation of CAT is changed, resulting in a different tendency of pH tolerance from free enzymes. In addition, the anti-surfactant performance of the enzyme-carrying microspheres is improved (85.82% of relative enzyme activity remains in the presence of sodium lauryl sulfate). The reasons might be that the calcium carbonate mineral shell can stabilize the three-dimensional structure of the enzyme during the process of immobilizing the enzyme, resulting in the enhanced stability of the immobilized enzyme. Finally, the enzyme-carrying microspheres can completely remove the residual hydrogen peroxide from the gauze after bleaching within 25 min, which has a faster removal rate than the free enzyme (35 min).

Key words: hydrogen peroxide, catalase, calcium carbonate, bleach

CLC Number: 

  • TQ423