The Fermentation Broth of Streptomyces noursei Strain S86 as a Potential Biocontrol Product for Fusarium Crown Rot of Wheat

Fusarium crown rot of wheat, caused by Fusarium pseudograminearum, significantly affects the yield and quality of wheat worldwide. Here, Streptomyces noursei strain S86 (herein referred to as S86) was evaluated for its biocontrol efficacy and biochemical characteristics. Strain S86 was found to secrete cellulase, amylase, and other enzymes. Whole-genome sequencing and LC-MS analyses confirmed that S86 could produce toyocamycin, nystatin, anisomycin, natamycin, and other antimicrobial metabolites. The fermentation broth of S86 inhibited the growth of F. pseudograminearum and had broad-spectrum inhibitory activity against Rhizoctonia cerealis, Cochliobolus sativus, Fusarium graminearum, and Gaeumannomyces graminis var. graminis. A greenhouse experiment demonstrated that wheat seeds coated with the S86 fermentation broth showed better control efficiency against Fusarium crown rot (68.33%), which was 22.63% higher than direct root irrigation with the S86 fermentation broth. These results indicate that S86 fermentation products have the potential to be developed as biological controls of Fusarium crown rot disease in the field.