ANTAGONISTIC EFFECT OF THREE FUNGAL ISOLATES TO AFLATOXIN-PRODUCING^spergiY/HS/JavHS
Aflatoxin contamination in preharvest peanuts can be controlled among others by using antagonistic fimgi
to aflatoxin-producing fungi.Â Aspergillus flavusÂ is one of the fungal species where certain strains can produce
aflatoxin. Informations regarding the type of interactions between antagonistic fungi and toxigenic A. flavus, and the
effects of culture filtrates of the test fungi on the growth and aflatoxin production of toxigenic A. flavusÂ are
necessary, before antagonistic fungi could be used as biocontrol agent. Three fungal isolates (nontoxigenic A.
flavus BIO 2127, A. niger BIO 2129 and Trichoderma harzianum BIO 19130) were tested for their antagonistic
properties against toxigenic A. flavus BIO 2132 using direct and indirect confrontation methods.
On direct confrontation method, four kinds of agar media were used, i.e PDA (Potato Dextrose Agar), MEA
1% (Malt Extract Agar 1%), SMKYA (Sucrose 200 g, MgSO47H2O 0.5 g, KNO3 3 g, yeast extract 7 g, and block agar
AA 20 g), and the mixture of MEA 1 % + SMKYA (1:1). The results indicated that the type of interactions between
toxigenic A. flavus either with nontoxigenic A. flavus or with T. harzianum was B type. In this type of interaction,
the growth of both toxigenic A. flavus and the test fungi inhibited each other (mutual inhibition) with the zone of
inhibition < 2 mm. Type of interaction between toxigenic A. flavus and A. niger depended on the kind of media. On
SMKYA and MEA 1% + SMKYA media, the interaction was B type, while on PDA and MEA 1% media it was
D type. In this D type of interaction, toxigenic A. flavus and A. nigerÂ inhibited each other (mutual inhibition) at a
distance > 2 mm.
Culture filtrates derived from nontoxigenic A. flavus and A. niger grown on ME 1%, SMKY and ME 1% +
SMKY inhibited the growth (based on dry weight) of toxigenic A. flavus, except culture filtrates derived from T.
harzianum grown on SMKY and ME 1% + SMKY media stimulated the growth of toxigenic A. flavus.
Culture filtrates of nontoxigenic A. flavus, A. niger and T. harzianum inhibited aflatoxin B\ production
of toxigenic A. flavus. Culture filtrates of A. niger and T. harzianum with conidial concentrations of IxlO6
Â and 3xl06
Â per ml inhibited aflatoxin B, production up to 100%. The percentage of inhibition of aflatoxin Bi
production increased with the increase of conidial concentrations of nontoxigenic A. flavus. The highest percentage
of inhibition of aflatoxin BI production (62.5%) was obtained from conidial concentration of 3xl06
Â per ml.
Aspergillus niger was the most potential fungus in inhibiting the growth of toxigenic A. flavus, either on
agar media or on culture filtrates of test fungi. Culture filtrate of A. niger was also the most potential filtrate in
inhibiting aflatoxin BI production of toxigenic A. flavus.
How to Cite
Authors who publish with this journal agree with the following terms:
- Authors retain copyright and grant the journal right of first publication, with the work 1 year after publication simultaneously licensed under a Creative Commons attribution-noncommerical-noderivates 4.0 International License that allows others to share, copy and redistribute the work in any medium or format, but only where the use is for non-commercial purposes and an acknowledgement of the work's authorship and initial publication in this journal is mentioned.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).