Reduction of Mycotoxigenic Fungi Growth and Their Mycotoxin Production by Bacillus subtilis QST 713

Abstract

The use of chemical pesticides to control the occurrence of mycotoxigenic fungi in crops has led to environmental and human health issues, driving the agriculture sector to a more sustainable system. Biocontrol agents such as Bacillus strains and their antimicrobial metabolites have been proposed as alternatives to chemical pesticides. In the present work, a broth obtained from a commercial product containing Bacillus subtilis QST 713 was tested for its ability to inhibit the growth of mycotoxigenic fungi as well as reduce their mycotoxin production. Mass spectrometry analysis of Bacillus subtilis broth allowed to detect the presence of 14 different lipopeptides, belonging to the iturin, fengycin, and surfactin families, already known for their antifungal properties. Bacillus subtilis broth demonstrated to be a useful tool to inhibit the growth of some of the most important mycotoxigenic fungi such as Aspergillus flavus, Fusarium verticillioides, Fusarium graminearum, Aspergillus carbonarius, and Alternaria alternata. In addition, cell-free Bacillus subtilis broth provided the most promising results against the growth of Fusarium graminearum and Alternaria alternata, where the radial growth was reduced up to 86% with respect to the untreated test. With regard to the mycotoxin reduction, raw Bacillus subtilis broth completely inhibited the production of aflatoxin B1, deoxynivalenol, zearalenone, and tenuazonic acid. Cell-free broth provided promising inhibitory properties toward all of the target mycotoxins, even if the results were less promising than the corresponding raw broth. In conclusion, this work showed that a commercial Bacillus subtilis, characterized by the presence of different lipopeptides, was able to reduce the growth of the main mycotoxigenic fungi and inhibit the production of related mycotoxins.

Biocontrol Capabilities of Bacillus subtilis E11 against Aspergillus flavus In Vitro and for Dried Red Chili (Capsicum annuum L.)

“…Studies have pointed out that Bacillus can produce various secondary metabolites and lytic enzymes in the metabolic process, which play an important role in the antagonism of Bacillus [ 48 ]. The ability of B. subtilis E11 screened in this experiment to reduce AFB 1 was higher than that of some reported strains.…”

“…B. subtilis is one of the most commonly used microorganisms in the industry for producing lipopeptides, which have wide applications in biology (anti-bacterial, anti-fungal, anti-viral, and anti-tumor), chemical, agricultural, pharmaceuticals, and food industries [ 56 ]. Bertuzzi et al [ 48 ] analyzed the lipopeptides in raw and cell-free B. subtilis QST 713 broth by LC-MS/MS, and found that the contents of surfactants, iturins, and fengycin family in the broth were 292 mg/L, 3034 mg/L, and 1033 mg/L, respectively. However, the content of all three lipopeptides in cell-free broth was lower than that in raw broth.…”

Enhancement of agri-food by-products: green extractions of bioactive molecules with fungicidal action against mycotoxigenic fungi and their mycotoxins

“…The diameter of the fungal colonies was measured along two perpendicular diagonals crossing the inoculum point. The percentage reduction in fungal growth in the presence of the extracts was calculated by comparing the fungal growth diameters obtained in untreated dishes with the fungal growth diameters obtained in the presence of each extract ( 26 ).…”

Genetically Modified Plants Based on Bacillus Genes and Commercial Bacillus-Based Biopesticides for Sustainable Agriculture

“…Bacillus strains have been intensively used against Fusarium [15][16][17][18][19] and Aspergillus [20][21][22] species. Also, Bacillus-based biocontrol has been used to decrease mycotoxin contamination in crops [23][24][25]. The studies devoted to lower mycotoxin content in GM-Bt plants (maize) [26][27][28] should also be mentioned.…”