Opportunities and constraints in the development of antagonistic yeasts for the control of postharvest diseases of fruit

Purpose of review: This review focuses on the main achievements of research in the field of biological control with microorganisms against postharvest diseases of fruit.

Findings: Biological control using microbial antagonists is one of the most promising alternatives for reducing fungicide use during the postharvest life of fruit. When considering how to improve the performance of natural biocontrol agents (BCAs), the comprehen sion of the mechanisms of action is an essential step. Advanced molecular techniques are substantially contributing to improving the knowledge of the antagonistic mechanisms of BCAs. The registration of a specific strain of an antagonist requires precise identification and genetic stability. Molecular approaches can help to differentiate a BCA from an epiphytic microorganism. Another important issue is the industrialisation of the microorganism in order to obtain a marketable biofungicide that involves the optimisation of the mass production process and the development of appropriate stabilisation and formulation to extend the shelf life of the biocontrol product.

Directions for future research: Strong efforts should be devoted to deepening the knowledge related to the mechanisms of action used by potential BCAs to control postharvest pathogens. Current fast developments in genomics and proteomics will allow the deter mination and monitoring of changes in the physiological status of BCAs and the effect of environmental stress. Changes in the expres sion levels of key biocontrol genes during mass production, stabilisation, formulation and fruit storage will allow clarification of the science of postharvest biocontrol. Moreover research is needed in order to improve the viability, efficacy and shelf life of potential biocontrol agents, by modifying and optimising the fermentation, stabilisation and production processes.