Soil microbial communities perform key ecosystem functions- nutrient and carbon cycling, supporting plant-soil interactions, and shaping the soil habitat. With increasing use of microbial-based products, their microbial ingredients can enter soil via wastewater, runoff, or direct misuse. If introduced, they have the potential to influence the resident soil-community composition and function, necessitating the identification of factors that could enable introduced microbes to disturb soil microbial communities. To understand a representative range of potential interactions that could be expected in soil, five Bacillus spp. isolated from a microbial-based cleaning product were characterised using a three-factor approach encompassing: (1) abiotic environmental filters (pH 3–9, 12–37 °C, 0–22% NaCl), (2) intrinsic traits linked to persistence and niche modification (biofilm formation and pH shift), and (3) biotic interaction outcomes with 69 soil-derived bacteria using supernatant assays. All isolates grew across pH 5–9 and shifted surrounding pH toward neutrality, indicating niche modification capacity. Two isolates formed biofilms also grew at pH 4, suggesting enhanced persistence. Salinity response curves showed unimodal optima (~1.7–3.5% NaCl) with tolerance beyond the optimum (up to 10%). Together, indicating wide soil persistence ability. Pairwise interactions with soil strains revealed inhibitory, neutral, and positive interactions. Two biofilm formers demonstrated a higher proportion of positive growth promoting effects in supernatant assays, with a moderate positive association (Pearson’s r = 0.48) in interaction outcomes. Integrating these findings, the next step is to assemble a 69-member synthetic-soil community to test the potential effect of introducing the probiotics in the community.