In vitro interaction of actinomycetes isolates with Aspergillus flavus: impact on aflatoxins B1 and B2 production.
This work aimed to study the interaction between Actinomycetal isolates and Aspergillus flavus to promote mutual antagonism in contact. Thirty-seven soilborn Streptomyces spp. isolates were chosen as potential candidates. After a 10-day in vitro co-incubation period, 27 isolates respond to the criteria, that is, mutual antagonism in contact. Further aflatoxins B1 and B2 analysis revealed that those 27 isolates reduced aflatoxin B1 residual concentration from 38·6 to 4·4%, depending on the isolate. We selected 12 isolates and tested their capacity to reduce AFB1 in pure culture to start identifying the mechanisms involved in its reduction. AFB1 was reduced by eight isolates. The remaining AFB1 concentration varied between 82·2 and 15·6%. These findings led us to suggest that these eight isolates could be used as biocontrol agents against AFB1 and B2 with low risk of impacting the natural microbial equilibrium.


CONCLUSIONS
Interaction between Aspergillus flavus and Actinomycetes isolates was conducted in vitro. Actinomycetes isolates having a mutual antagonism in contact with A. flavus were chosen for further aflatoxins production study. This is a new approach based to develop biocontrol against aflatoxins accumulation in maize while respecting natural microbial equilibrium.
Laboratoire de Génie Chimique, Université de Toulouse, INP-ENSAT, Castanet-Tolosan, France.
C
C
Verheecke
T
T
Liboz
M
M
Darriet
N
N
Sabaou
F
F
Mathieu
D039903:Actinobacteria / Q000302:isolation & purification / Q000502:physiology*; D016604:Aflatoxin B1 / Q000096:biosynthesis*; D000348:Aflatoxins / Q000096:biosynthesis*; D000898:Antibiosis; D001231:Aspergillus flavus / Q000254:growth & development / Q000378:metabolism*; D005516:Food Microbiology; D003313:Zea mays / Q000382:microbiology
D000348:Aflatoxins; C029753:aflatoxin B2; D016604:Aflatoxin B1
Aspergillus flavus; aflatoxins; antagonism; biocontrol; microbial interaction; streptomyces