Abstract:The mycotoxin deoxynivalenol, also called deoxynivalenol (DON), contaminates various crops including wheat and barley. In order to identify a bacterial strain capable of DON biodegradation, a total of 50 soil samples were collected. One white strain was obtained after enrichment, screening, and purification of bacterial strains and was named W-D; it could grow in an inorganic culture medium with DON (20 μg/mL) as the sole carbon source. Analysis of DON degradation ability of the isolated bacterial strain showed that the degradation rate could reach 40.40% after the strain acted on DON (60 μg/mL) at 180 r/min for seven days at 37 ℃. Microscopic analysis showed that the strain W-D was gram-negative and had a short rod-shaped structure. Scanning electron microscopy (SEM) revealed that the strain had a rod-like structure with varying shapes, and a size of about 0.5?1.0~3.0 μm. Further analysis showed that the physiological and biochemical characteristics of W-D were essentially consistent with those of Enterobacter spp. PCR amplification of the 16S ribosomal DNA (16S rDNA) of W-D strain yielded a fragment of ~1500 bp. Subsequent phylogenetic tree analysis indicated that the strain belonged to the genus Enterobacter, and was the most closely related to Enterobacter cloacae.
