Purification of a killer toxin from Aureobasidium pullulans for the biocontrol of phytopathogens.

The objectives of the present study were to purify and assess the killer toxin effect produced by Aureobasidium pullulans under casual agents of green mold (Penicillum digitatum) and sour rot (Geotrichum citri-aurantii). Initially, different methods of protein precipitation were tested. The proteolytic activity and the presence of proteins acting on cell wall receptors, β-1,3-glucanase and chitinase were determined, and toxin purification was conducted by Sephadex G-75 gel exclusion chromatography and cellulose chromatography (medium fibers).

Antifungal activity and action mechanisms of yeasts isolates from citrus against Penicillium italicum.

Penicillium italicum (Blue mold) is a major postharvest disease of citrus. An alternative to controlling the disease is through the use of yeasts. The purpose of the present study was to screen effective yeast antagonists against P.

Biocontrol ability and putative mode of action of yeasts against Geotrichum citri-aurantii in citrus fruit.

Sour rot is a major postharvest disease of citrus fruit and is caused by the fungal pathogen Geotrichum citri-aurantii. A lack of chemicals certified for the control of this disease has led to the consideration of alternative methods and strategies, such as the use of yeasts as biocontrol agents. The purpose of the present study was to test the ability of yeasts isolated from leaves, flowers, fruit, and soil, and six Saccharomyces cerevisiae isolates to control citrus sour rot, to assess the mechanisms of action of the yeast isolates that were demonstrated to be effective for biocontrol, and to identify the most effective yeast isolates for the biocontrol of G.

Saccharomyces cerevisiae: A novel and efficient biological control agent for Colletotrichum acutatum during pre-harvest.

In this study, we evaluated the efficiency of six isolates of Saccharomyces cerevisiae in controlling Colletotrichum acutatum, the causal agent of postbloom fruit drop that occur in pre-harvest citrus. We analyzed the mechanisms of action involved in biological control such as: production of antifungal compounds, nutrient competition, detection of killer activity, and production of hydrolytic enzymes of the isolates of S. cerevisiae on C.