Exploring the use of bacillomycin D to control citrus sour rot caused by Geotrichum citri-aurantii

Abstract

Geotrichum citri-aurantii is a main pathogen that causes severe postharvest citrus fruit disease and leads to economic losses. In this work, the antifungal activity of bacillomycin D against G. citri-aurantii FZ2 was investigated. The effectiveness of bacillomycin D on controlling citrus sour rot was also evaluated. The results indicated that bacillomycin D had strong antifungal activity on G. citri-aurantiis growth, and 12.24 μmmol/L of minimal inhibitory concentration (MIC) and 24.48 μmmol/L of minimal fungicidal concentration (MFC) were obtained. Bacillomycin D exerted destructive impacts on G. citri-aurantii mycelia and resulted in damage of cell integrity and increase of membrane permeability. When exposed to 48.96 μmol/L of bacillomycin D and stored the infected citrus fruit at 25 °C for 10 d, the citrus sour rot was completely suppressed. Moreover, bacillomycin D treatment could effectively improve citrus fruit quality and increase the resistance to G. citri-aurantii. Our findings showed that bacillomycin D could be used as a promising fungicide for controlling postharvest citrus sour rot and extending the shelf-life for citrus fruit storage.