Submitted to: Book Chapter
Publication Type: Book / chapter
Publication Acceptance Date: 9/25/2013
Publication Date: 12/1/2013
Citation: Hua, S.T. 2013. Biocontrol of Aspergillus flavus by Pichia anomala. In: Mendez-Vilas, A., editor. Microbial Pathogens and Strategies for Combating Them: Science Technology and Education. Vol. 2. Spain. Formatex Research Center. p 1067-1072. Interpretive Summary: The use of chemical fungicides has resulted in development of pest resistance and resurgence. In addition, use of fungicides in certain agricultural systems is impractical due to the expense, risk of environmental pollution, and negative effects to human health. Biological control of insect pests, plant pathogens, and weeds is the only major alternative to the use of pesticides in agriculture and forestry. Accordingly, microorganisms naturally present in agricultural ecosystems are being studied as environmentally compatible alternatives to traditional chemical methods for controlling plant diseases and fungi associated with mycotoxin production. Biological control can reduce the harmful effect of phytopathogenic or mycotoxigenic fungi while having a minimal impact on the environment. The potential of saprophytic yeasts to be used in applications for reducing aflatoxin contamination in food is the focus of this review.
Technical Abstract: Aflatoxins are extremely potent natural carcinogens and a major food safety concern because of potential contamination of food commodities. Threshold levels set by the U. S. Food and Drug Administration for aflatoxins in foods for domestic consumption are less than 20 parts/ billion (ppb). However, the European Union (EU) and Japan have set threshold levels at less than 4 ppb. These low tolerance levels increase potential for rejection of agricultural commodities from exporting countries. The major aflatoxin-producing fungus, Aspergillus flavus is ubiquitous in agricultural soils and has a broad ecological niche. The use of yeast as antagonists against Mycotoxin fungi is a promising approach to manage aflatoxin contamination via biological control. Research to enhance the effectiveness and mass production of biocontrol yeast will facilitate commercial product development for practical application. Pichia anomala WRL-076 has been demonstrated to reduce the spore production of A. flavus in both lab conditions and field experiments. Thus, P. anomala is likely to provide an economical means of managing aflatoxin contamination in food chain.