Research on Atomic Transfer Radical Polymerization Modified Lactic Acid Bacteria and Their Removal of Aflatoxin B₁

To study the new method of aflatoxin removal by Lactobacillus plantarum materials, and provide a new idea for the efficient biological removal of aflatoxin B₁, this study used the polydopamine-based atom transfer radical polymerization (p-ATRP) and cell-catalyzed copper-free atom transfer radical polymerization (c-ATRP) to modify the surface modification of living cells of Lactobacillus plantarum, and guided the self-assembly polymerization reaction within the ATRP system to form polymer materials, characterized the modified Lactobacillus plantarum and compared its adsorption and desorption capabilities towards aflatoxin B₁ before and after modification. Results showed that, the unmodified Lactobacillus plantarum had a smooth cell surface, while the Lactobacillus plantarum modified by p-ATRP had a very rough cell surface, and the Lactobacillus plantarum modified by c-ATRP had wrinkles on the cell surface. The Zeta point of unmodified Lactobacillus plantarum was -8.43 mV, while the points of Lactobacillus plantarum after PD and PNIPAAm modification were 1.791 and 13.767 mV, respectively. The adsorption rate of Lactobacillus plantarum for aflatoxin B₁ at concentrations ranging from 0.1~100 μg/mL was 75.3%. Furthermore, the adsorption capacity of p-ATRP and c-ATRP modified Lactobacillus plantarum exhibited an increase of 7.8% and 6.4%, respectively, compared with unmodified Lactobacillus plantarum. Additionally, at the same concentration of aflatoxin B₁, the desorption rate of Lactobacillus plantarum was 6.1%, while the desorption capabilities of p-ATRP and c-ATRP modified Lactobacillus plantarum were enhanced by 14.4% and 42%, respectively. Overall, the modified Lactobacillus plantarum demonstrated a significant enhancement in both adsorption and desorption abilities towards aflatoxin.