Open AccessThirteen novel deoxynivalenol‐degrading bacteria are classified within two genera with distinct degradation mechanisms
Author(s) -
Sato Ikuo,
Ito Michihiro,
Ishizaka Masumi,
Ikunaga Yoko,
Sato Yukari,
Yoshida Shigenobu,
Koitabashi Motoo,
Tsushima Seiya
Publication year - 2012
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2011.02461.x
Subject(s) - biology , mycotoxin , bacteria , fusarium , microbiology and biotechnology , secondary metabolite , food science , botany , biochemistry , genetics , gene
The mycotoxin deoxynivalenol ( DON ), a secondary metabolite produced by species of the plant pathogen F usarium , causes serious problems in cereal crop production because of its toxicity towards humans and livestock. A biological approach for the degradation of DON using a DON ‐degrading bacterium ( DDB ) appears to be promising, although information about DDB s is limited. We isolated 13 aerobic DDB s from a variety of environmental samples, including field soils and wheat leaves. Of these 13 strains, nine belonged to the G ram‐positive genus N ocardioides and other four to the G ram‐negative genus D evosia . The degradation phenotypes of the two G ram types were clearly different; all washed cells of the 13 strains degraded 100 μg mL −1 DON to below the detection limit (0.5 μg mL −1 ), but the conditions inducing the DON ‐degrading activities differed between the two G ram types. The HPLC profiles of the DON metabolites were also distinct between the two genera, although all strains produced 3‐epi‐deoxynivalenol. The G ram‐positive strains showed DON assimilation in media containing DON as a carbon source, whereas the G ram‐negatives did not. Our results suggest that aerobic DDBs are distributed within at least two phylogenetically restricted genera, suggesting independent evolution of the DON‐degradation mechanisms.