Serratia plymuthica is a ubiquitous bacterium with broad ecological relevance that can be isolated from soil, water, insects, plants, and fruits. Although widely distributed, it is most frequently isolated from the plant rhizosphere, where it occurs both as a free-living rhizobacterium and as a non-rhizobial endophyte. While several Serratia species are recognized as opportunistic pathogens (e.g., Serratia marcescens), S. plymuthica is primarily recognized for its beneficial interactions with plants and is widely regarded as a plant growth-promoting and biocontrol bacterium.