Abstract Plant growth-promoting microorganisms such as Bacillus sp. can be applied such as microbial biocontrol agents to promote sustainable agriculture and reduce dependency on chemical pesticides. B. subtilis group species have been employed to enhance plant growth and promotion or to control pathogens of some crops due to their capacity to produce a wide array of secondary metabolites with different biological activities. However, not all these species have the same ability to stimulate plant growth or the same antifungal activity. The objective of this study was to conduct a comparative analysis of the plant growth-promoting properties of B. subtilis ELI204, B. subtilis ELI239, B. velezensis ELI71, and B. amyloliquefaciens ELI203, all belonging to the B. subtilis group, while also comparing their antifungal activity. This comparison can provide insight into which metabolites are responsible for their function in plants. The data showed that the crude extract of B. subtilis ELI239 and B. amyloliquefaciens ELI203 inhibited various fungi at rates ranging from 67% to 97%, depending on the fungi. The four strain crude extracts were probed in four plants such as, chickpea ( Cicer arietinum L.), lentils ( Lens culinaris ), maize ( Zea mays var. amylacea ) and radish ( Raphanus sativus) , both in germination and plant growth development stages, identifying which strain is the best to apply on plants. Pot experiments demonstrated that B. subtilis ELI239 and B. amyloliquefaciens ELI203 significantly enhanced plant growth. The capacity of these species to produce natural compounds was studied to analyze the chemical profile of each species and what relations had with their role in plants. B. subtilis ELI239 and B. amyloliquefaciens ELI203 produced macrolactin A, which can be involved in the strong antifungal activity of both strains.
Calderón et al. (Fri,) studied this question.