Research Articles
The Rector, Prof. Pier Sandro Cocconcelli of IASA — Institute of Advanced Science for Agriculture — together with a group of researchers, recently contributed to a study focused on assessing the safety of microbial biostimulants, innovative tools capable of promoting crop growth and resilience while reducing dependence on synthetic fertilizers. The international study was published in the journal MICROBIAL GENOMICS
As part of IASA’s research activities, the analysis of biological processes is central to developing sustainable, safe, and effective solutions to support the agri-food supply chain. In this context, it is important to focus on assessing the safety of microbial biostimulants—innovative tools capable of promoting crop growth and resilience while reducing dependence on synthetic fertilizers.
Microbial biostimulants (MBs) represent one of the most promising frontiers for sustainable agriculture, as they enhance nutrient uptake efficiency, support plant physiological processes, and contribute to maintaining soil organic matter. However, since these microorganisms are intentionally introduced into the environment, it is essential to ensure their safety through rigorous evaluation protocols. As reported in the article, the study proposes an integrated approach based on whole-genome sequencing (WGS) combined with an extensive literature search (ELS).
The research analyzed the genetic makeup of various microbial species used as agricultural biostimulants, including both microorganisms belonging to groups already recognized as safe under the Qualified Presumption of Safety (QPS) principle and genera for which specific regulatory guidelines are not yet available. The analysis examined the presence of potential virulence factors, genes associated with antimicrobial resistance, and mobile genetic elements, assessing the potential risk of horizontal transfer of undesirable traits.
The results confirmed the high safety profile of the microorganisms belonging to the analyzed QPS groups, in which no virulence factors were detected and the identified antimicrobial resistances were found to be limited and unrelated to clinically relevant phenomena.
For microorganisms not belonging to the QPS groups, the study highlighted the presence of certain genomic markers that require in-depth case-by-case evaluation. In particular, within the genera Azotobacter and Azospirillum, certain genes were identified that are associated with functions which, in most cases, are related to beneficial interactions with plants rather than pathogenic traits. Furthermore, the antimicrobial resistances observed are primarily attributable to intrinsic mechanisms, such as efflux pumps, and not to easily transferable elements.
A particularly significant finding concerns the identification, in the genera Azospirillum and Herbaspirillum, of specific chromosomal β-lactamases: although these genes share structural similarities, they are genetically distant from clinically relevant variants, and the absence of mobile genetic elements suggests a low risk of spread through horizontal transfer.
Overall, the study demonstrates how the integration of advanced genomic analysis and a review of the scientific literature can serve as a reliable tool for assessing the safety of microbial biostimulants, contributing to the development of a more sustainable and innovative agriculture.
This research is part of IASA’s scientific mission, which is focused on promoting interdisciplinary approaches that combine technological innovation, environmental protection, and food safety, while supporting the role of advanced research as a driver of transformation in contemporary agricultural systems.
Source: https://www.microbiologyresearch.org/content/journal/mgen/10.1099/mgen.0.001391#tab2-Comprehensive genome-wide analysis for the safety assessment of microbial biostimulants in agricultural application- Bellotti, Gabriele; Cortimiglia, Claudia; Antinori, Maria Elena; Cocconcelli, Pier Sandro; Puglisi, Edoardo, 2025
