Structure-Activity Relationship of Acrylamide Adsorption by Peptidoglycan of Lactic Acid Bacteria

This research investigated the peptidoglycan (PG) extracted from five strains of lactic acid bacteria (Lactobacillus plantarum ATCC8014, Lactobacillus plantarum 806, Lactobacillus plantarum 1.0665, Lactobacillus casei ATCC393 and Lactobacillus acidophilus KLDS1.0307), focusing on the correlation between PG's structural configurations and its ability to adsorb acrylamide (AA). A comprehensive analysis was conducted to examine the chemical, microscopic, and surface structures of PG. The findings showed that PG from Lactobacillus plantarum ATCC8014 possessed the superior AA adsorption rate of 89.93%. Chemical structure analysis indicated that increments in the PG's hexosamine content, sugar chain length, and glutamic acid content were significantly and positively linked to an increased AA adsorption capacity, with the rate escalated from 56.76% to 89.93%. The utilization of aspartic acid as a peptide bridge was identified as more effective for AA adsorption by PG than serine, achieving the highest adsorption rate increment of 33.17%. Conversely, heightened PG acetylation was associated with a diminished AA adsorption rate, with respective declines of 29.62%, 34.00%, 41.96%, and 69.03%. Microstructural evaluation revealed a positive correlation between the specific surface area and pore volume of PG and the adsorption rate. Lactobacillus plantarum ATCC8014 PG exhibited the most considerable specific surface area (0.9857 m²/g) and pore volume (0.0056 cm³/g), which corresponded to its highest AA adsorption rate of 89.93%. Conversely, Lactobacillus acidophilus KLDS1.0307 PG, with the largest pore size (49.2072 nm), presented the lowest AA adsorption rate of 56.76%, indicating a negative correlation. The surface structure analysis recommended that the roughness of PG did not significantly influence its ability to adsorb AA. The study's conclusions underscore the influence of PG structural diversity on AA adsorption efficacy, offering references for advancing the understanding of biological detoxification mechanisms in lactic acid bacteria PG.