Rice Phyllosphere Bacillus Species and Their Secreted Metabolites Suppress Aspergillus flavus Growth and Aflatoxin Production In Vitro and In Maize Seeds
The emergence of super-toxigenic strains by recombination is a risk from an intensive use of intraspecific aflatoxin (AF) biocontrol agents (BCAs). Periodical alternation with interspecific-BCAs will be safer since they preclude recombination. We are developing an AF-biocontrol system using rice-ass...
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Published in | Toxins Vol. 10; no. 4; p. 159 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Switzerland
MDPI AG
16.04.2018
MDPI |
Subjects | |
Online Access | Get full text |
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Summary: | The emergence of super-toxigenic strains by recombination is a risk from an intensive use of intraspecific aflatoxin (AF) biocontrol agents (BCAs). Periodical alternation with interspecific-BCAs will be safer since they preclude recombination. We are developing an AF-biocontrol system using rice-associated
reported previously (RABs). More than 50% of RABs inhibited the growth of multiple
strains, with RAB4R being the most inhibitory and RAB1 among the least. The fungistatic activity of RAB4R is associated with the lysis of
hyphal tips. In field trails with the top five fungistatic RABs, RAB4R consistently inhibited AF contamination of maize by Tox4, a highly toxigenic
strain from Louisiana corn fields. RAB1 did not suppress
growth, but strongly inhibited AF production. Total and HPLC-fractionated lipopeptides (LPs) isolated from culture filtrates of RAB1 and RAB4R also inhibited AF accumulation. LPs were stable in vitro with little loss of activity even after autoclaving, indicating their potential field efficacy as a tank-mix application.
colonization and AF were suppressed in RAB1- or RAB4R-coated maize seeds. Since RAB4R provided both fungistatic and strong anti-mycotoxigenic activities in the laboratory and field, it can be a potent alternative to atoxigenic
strains. On the other hand, RAB1 may serve as an environmentally safe helper BCA with atoxigenic
strains, due its lack of strong fungistatic and hemolytic activities. |
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ISSN: | 2072-6651 2072-6651 |
DOI: | 10.3390/toxins10040159 |