P-044 - Development of biological control agent to reduce aflatoxin contamination in corn

Tuesday, August 5, 2025

9:30 AM - 10:15 AM HST

Location: Exhibit Hall 3

Author(s)

LR

Lindsey P. Robinson

Mississippi State University
Mississippi State, Mississippi, United States
EW

Emma P. Willis

Mississippi State University
Mississippi State, Mississippi, United States
WP

Westin P. Phillips

Mississippi State University
Mississippi State, Mississippi, United States
EA

Ehtasham P. Ali

Mississippi State University
Mississippi State, Mississippi, United States
DJ

Dan Jeffers

USDA-ARS Corn Host Plant Resistance Research Unit
Mississippi State, Mississippi, United States
EB

Ebrahiem Babiker

Supervisory Research Geneticist and Research Leader
USDA-ARS Corn Host Plant Resistance Research Unit
Mississippi State, Mississippi, United States

Presenting Author(s)

SL

Shien Lu

Mississippi State University
Mississippi State, Mississippi, United States

Abstract Text: Aflatoxins produced by Aspergillus spp. pose a significant threat to food safety globally. Biocontrol methods have drawn a great deal of attention to address this problem in several commodities. The endophytic bacterium Burkholderia sp. strain MS455 exhibits antifungal activity against Aspergillus flavus (AF). To develop a formulation, survival capacity and antimicrobial activity in different carriers were evaluated. Plate bioassays indicate that MS455 maintains ~90% of viability and antimicrobial activity in nutrient-broth yeast extract (NBY) broth and phosphate buffer (PB, 0.01M, pH 7.2) for 10 weeks at 22^oC. For the field trial, two corn hybrids DKC88-69 and PI1870YHR were used. A 20 µL mixture of MS455 (10⁸ cells/ml), the AF strain NRRL 3357 (10⁸ spores/ml), and a liquid formulation carrier (0.1%) was used to inoculate the corn ears via wounding two weeks after mid-silk. Fungal growth and aflatoxin concentration were measured 8 weeks after inoculation. Fungal growth was inhibited on both hybrids treated with MS455 in NBY and PB while aflatoxin levels were significantly (P< 0.05) reduced on PI1870YHR, but not DKC88-69, although some reduction was observed. Bioinformatic analyses revealed that the MS455 genome not only harbors a genetic locus homologous to the ocf gene cluster, which produces the antifungal occidiofungin, but also carries genetic loci homologous to biosynthesis genes of antimicrobials pyrrolnitrin and ornibactin. This research has provided valuable insights for development of MS455 as a biocontrol agent to reduce aflatoxin contamination on corn.