Modified attapulgite-laccase composites for aflatoxin B1 detoxification: Performance, toxicity, and mechanistic insights.

Abstract

Aflatoxin B1 (AFB1) poses significant threats to both health and the economy. Recently, integrated technologies have emerged as a novel detoxification strategy. However, most current research remains at the laboratory stage, impeded by high costs, unknown toxicity of degradation products, and complex, time-consuming processes. In this study, a promising adsorption-biocatalytic system for AFB1 detoxification using engineered attapulgite-laccase composites (L-AATP) was constructed. L-AATP exhibited greater stability than laccase. Moreover, it displayed a strong detoxification ability, achieving a detoxification efficiency of 670 ng/mg. The 13 putative AFB1 degradation products were tentatively assigned by LC-MS, and three potential degradation pathways were proposed with support from density functional theory (DFT) calculations. Theoretical calculations suggested that the furan ring double bond may be a susceptible site for electrophilic addition, while lactone-ring hydrolysis and opening were also thermodynamically feasible. Toxicity assessment using the T.E.S.T. program predicted that most degradation intermediates generated during L-AATP-mediated detoxification may have lower toxicity than AFB1. An in vitro viability assay demonstrated low cytotoxicity of L-AATP to IPEC-J2 cells. To assess the potential applicability of immobilized laccase, its performance was evaluated in contaminated peanut meal under simulated gastrointestinal conditions. A straightforward detoxification procedure was established: blending L-AATP with contaminated peanut meals at a mass ratio of 1:1000, which was appropriate when contamination levels do not surpass 300 μg/kg. In addition, L-AATP was an easy-to-operate, low-cost, long-term effective detoxifying agent, with negligible nutritional impact on peanut meals. This work not only developed a novel mycotoxin detoxifier but also provides new insights into the joint application of multiple technologies to enhance detoxification efficacy.