This study was conducted to evaluate the efficacy of the biocontrol yeast, Rhodotorula glutinis with a
surfactant produced by Pseudomonas aeruginosa, rhamnolipids, on the inhibition of Alternaria alternata
on cherry tomato fruit. A combination of R. glutinis with rhamnolipids at 500 g/mL was more effective
in suppressing A. alternata infection than application of R. glutinis or rhamnolipids alone. Moreover,
integration of R. glutinis with rhamnolipids significantly stimulated peroxidase, polyphenoloxidase and
phenylalanine ammonialyase activities of cherry tomato fruit, which were stronger than the single treatments.
Rhamnolipids with reduced concentrations did not affectthe growth of R. glutinis in vitro, but were
utilized as carbon sources by yeasts under conditions of limited carbon sources. Moreover, rhamnolipids
themselves reduced decay incidence of A. alternata on cherry tomato fruit and promoted the population
growth of R. glutinis in vivo. This combined treatment could induce natural resistance as well as accelerate
colonization of yeasts on the fruit surface, providing an effective and safe strategy to control postharvest
diseases.