Minimal adverse effects of exogenous phage treatment on soil bacterial communities

Bacterial plant pathogens pose significant challenges to global food production, leading to antibiotics and copper being used for their control. Bacteriophages (or phages), which infect bacterial pathogens, have been proposed as an environmentally friendly alternatives for managing these pathogens in crops. However, whether the release of phages into the environment can be considered safe and environmentally friendly has not been well studied. Here, we examined whether the exogenous treatments of various phages with biocontrol potential against Erwinia amylovora, Pectobacterium odoriferum, and Pseudomonas syringae pv. actinidiae impact bacterial communities within soils. To achieve this, five different phages infecting three distinct host bacteria were individually introduced into in soils obtained from an apple orchard, kimchi cabbage field, and a kiwifruit orchard. After one week of phage treatment, soil microbiomes were analyzed using the 16S rRNA gene-based approach. The microbiome analysis results revealed that the phage treatments did not alter the alpha and beta diversities of the bacterial communities, irrespective of the phage types used. Moreover, the overall distribution of microbial taxa remained unaffected by the phage treatment, although slight changes were observed in the abundance of a few taxa. These results indicate that the adverse effects of exogenous phage treatment on soil bacterial communities are minimal, thus the phage treatment in soils can be considered an environmentally friendly strategy.