Physicochemical Properties and Antibiosis Activity of the Pink Pigment of Erwinia persicina Cp2

The control and management of fungal diseases is a worldwide problem. A variety of microbial pigments have excellent antibacterial effects, and naturally occurring bacterial pigments may help in tackling fungal diseases. In order to explore the basic properties and biological functions of the pink pigment produced by Erwinia persicina Cp2, we used organic solvents to extract the pink pigment, analyzed the physicochemical properties of the pigment, determined the chemical composition using ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and selected five pathogenic fungi to study the inhibitory effects of the pink pigment. The results showed that the main component of the pink pigment was usambarensine, which had a good light stability and a good temperature stability at room temperature (<40 °C), but the influence of the oxidant on its activity was greater than that of the reductant; simultaneously, we found that strong acids, strong alkalis, Cu 2+ , and Zn 2+ all greatly affect the stability of the pink pigment, while Fe 2+ and Fe 3+ made the pigment darker. Meanwhile, the pigment could exert a good inhibitory effect against four plant pathogenic fungi: Alternaria solani , Sclerotinia sclerotiorum , Rhizoctonia solani , and Fusarium proliferatum . However, the inhibition of Fusarium oxysporum . f. sp cucumerinum decreased significantly in the later stages. This study had detected the purification process and antifungal activity on five fungi of the pink pigment of Erwinia persicina Cp2. It lays a theoretical and practical foundation for the production of related biological agents.