Evaluation of Rhodosporidium fluviale as biocontrol agent against Botrytis cinerea on apple fruit.

The aim of the present work was to evaluate the ability of the native yeast Rhodosporidium fluviale to control Botrytis cinerea on apple fruit and to study the possible mechanisms of action with the goal of improving the control of gray mold. For this, the influence of application time of the yeast was studied simulating preventive and curative effects. Also, the effect of nonviable cells of the yeast in the biocontrol was assessed. According to the results obtained, the following mechanisms of action of R. fluviale could be proposed: 1- competition for space, 2- direct interaction between antagonist and pathogen, 3- induction of ß-1,3-glucanase in apple tissue, 4- Probable production of glucanase in the apple wounds and 5- antifungal action of cellular components, probably chitin, present in the wall of yeast cells that could be the explanation for the activity of nonviable cells. SIGNIFICANCE AND IMPACT OF THE STUDY: Significance and Impact of the Study: Botrytis cinerea Pers: Fr, which causes gray mold of fruits and vegetables around the world, is difficult to control successfully because it is genetically variable and rapidly develops resistance to the chemicals commonly used for its control. This study is a contribution to the biocontrol of this phytopathogen fungus. The evaluation of the native yeast Rhodosporidium fluviale as biocontrol agent and the elucidation of possible mechanisms of action, including the participation of nonviable cells of this yeast, have not been reported up to date.

A novel solid phase extraction--ultra high performance liquid chromatography-tandem mass spectrometry method for the quantification of ochratoxin A in red wines.

A novel and advanced technology on solid phase extraction column prior to liquid chromatography coupled to tandem mass spectrometry has been used for the determination of ochratoxin A in red wine samples. Due to the need of a reliable and rugged method according to current regulations and with the aim of minimize heuristic efforts associated with analytical method development, the statistical design of experiment was employed. On other hand, the method validation according to European Commission 2002/657/EC was achieved. The values obtained for decision limit (CCα), detection capability (CCß), limits of detection and quantification were 0.07 µg L(-1), 0.14 µg L(-1), 0.13 µg L(-1) and 0.41 µg L(-1), respectively. The recoveries values were ranged from 95.7% to 107.2%. These values were compatible with the 2.0 µg L(-1) maximum allowable concentration limit established by different international regulations.