Optimization of Cultivation Parameters for Scale-Up Production of Streptomyces recifensis SN1E1

This study evaluated the growth characteristics and formulation stability of Streptomyces recifensis SN1E1, a potent antagonist against the apple fire blight pathogen Erwinia amylovora, and to establish optimal conditions for its large-scale cultivation and shelf-life formulation for sustainable agricultural use. We investigated specific carbon sources and formulation matrices to enhance growth, sporulation, and storage viability. Experimental results indicated that the addition of D-mannitol significantly expedited spore formation and promoted the overall growth of strain SN1E1. Furthermore, to ensure product stability, various preservative concentrations and formulation bases were assessed. Among the formulations tested, a mixture containing 0.02% soya and 5% skim milk exhibited the highest bacterial cell survival rate under storage conditions. The study suggested that D-mannitol is a favorable carbon source for the efficient sporulation of S. recifensis SN1E1 and confirms that a soya/skim milk-based formulation significantly improves the stability of the final product. These protocols provide a reliable foundation for the commercialization of this biocontrol agent. This study offers essential technical insights into the mass cultivation and preservation of plant growth-promoting Streptomyces species, facilitating their practical application in combating crop diseases like apple fire blight.