Bacterial Epimerization as a Route for Deoxynivalenol Detoxification: the Influence of Growth and Environmental Conditions

Abstract

Deoxynivalenol (DON) is a toxic secondary metabolite produced by several Fusarium species that infest wheat and corn. Food and feed contaminated with DON pose a health risk to both humans and livestock and form a major barrier for international trade. Microbial detoxification represents an alternative approach to the physical and chemical detoxification methods of DON-contaminated grains. The present study details the characterization of a novel bacterium, Devosia mutans 17-2-E-8, that is capable of transforming DON to a non-toxic stereoisomer, 3-epi-deoxynivalenol under aerobic conditions, mild temperature (25–30°C), and neutral pH. The biotransformation takes place in the presence of rich sources of organic nitrogen and carbon without the need of DON to be the sole carbon source. The process is enzymatic in nature and endures a high detoxification capacity (3 μg DON/h/108 cells). The above conditions collectively suggest the possibility of utilizing the isolated bacterium as a feed treatment to address DON contamination under empirical field conditions.

Strategies and Methodologies for Developing Microbial Detoxification Systems to Mitigate Mycotoxins

“…A number of studies have evaluated intrinsic factors, including carbon source [26,34], nitrogen source [26,34,88], vitamins [26], metals ions [12,34,46,89,90,91,92,93], enzyme inhibitors and promoters [52,89,90,91,92,93,94], initial concentration of mycotoxins [93,95], initial concentration of cells [53,95] and initial pH value [12,14,17,26,31,34,41,46,54,60,88,89,95,96], as well as extrinsic factors, including temperature [12,14,17,25,26,31,34,38,41,46,52,54,60,88,89,95,96], aeriation (shaking rate) [26], oxygen preference [14], as well as pre-incubation [26] and incubation time [34,97]. The experimental designs and optimized biotransformation conditions are summarized in Table 2.…”

Isolation and characterization of a novel deoxynivalenol-transforming strainParadevosia shaoguanensisDDB001 from wheat field soil

“…It was reported that Devosia mutans 17‐2‐E‐8 had the capacity to transform DON at rates close to 0·3 μ g h −1 per 10 7 cells with its exponential growth phase (He et al . ). It appears that DON‐transformation efficiency of strain DDB001 (6·8 μ g h −1 per 10 7 cells) is higher than that of strain 17‐2‐E‐8.…”

Deoxynivalenol: Masked forms, fate during food processing, and potential biological remedies

“…(2015) and He et al. (2016) observed that Devosia mutans 17‐2‐E‐8 from soil completely converted DON into the major metabolite 3‐keto‐DON and the secondary metabolite 3‐epi‐DON under aerobic conditions. Carere, Hassan, Lepp, and Zhou (2018) and Hassan et al.…”

“…Paenibacillus polymyxa also inhibited the growth of F. graminearum and the production of DON under greenhouse conditions (He, Boland, & Zhou, 2009). He et al (2015) and He et al (2016) observed that Devosia mutans 17-2-E-8 from soil completely converted DON into the major metabolite 3-keto-DON and the secondary metabolite 3-epi-DON under aerobic conditions. Carere, Hassan, Lepp, and Zhou (2018) and Hassan et al (2017) investigated the relevant enzymatic mechanism underlying epimerization.…”