Construction of Deoxynivalenol Enrichment and Detection System Based on Magnetosome Surface Display

Abstract

Deoxynivalenol (DON) is a mycotoxin commonly found in cereals. It has strong toxicity with high stability, thus it is easy to remain in food and cause serious poisoning symptoms to consumers. To establish an efficient and simple DON detection system, a biological nano magnetic particle called bacterial magnetosomes (BMs) extracted from magnetotactic bacteria with ultrasonic crushing and magnetic adsorption was used in this study. A single-stranded DNA aptamer specifically binding to DON was coupled to the surface of MBs by two different crosslinking agents, glutaraldehyde and polyethyleneimine (PEI), respectively, to synthesize two kinds of BMs-aptamer complexes for enriching DON. Then, the adsorption rate of the complex to DON was determined by HPLC. In the results, the absolute DON adsorption capacity of 1 mg BMs-aptamer complex was 27.24 ng when glutaraldehyde was used as crosslinker and 27.64 ng when PEI was used as crosslinker. The optimization results of desorption conditions showed that under the optimal elution conditions (DNase I+methanol for 2 times), the elution rate of DON adsorbed by BMs-glutaraldehyde-aptamer reached 72.7%, while the elution rate of DON adsorbed by BMs-PEI-aptamer complex reached 64.1%. Overall, the current study enriched the applications of magnetosomes in mycotoxin detection, and also provides new idea for the efficient enrichment and recovery of DON.