What Is a Sporulating Microbial Biostimulant?
A microbial biostimulant is a preparation containing live micro-organisms that, once in contact with the rhizosphere, activate natural growth and protection mechanisms in the plant. It is not a fertilizer, it does not supply nutrients directly. It acts on the plant's ability to mobilize what is already present in its environment. The term sporulating is critical. The strains we use at Ulysse Biotech are primarily Bacillus and Paenibacillus. They form endospores, an extremely resistant dormant form that survives heat, desiccation, and pH fluctuations. This property guarantees the viability of bacterial products for 24 months in liquid formulation, ensuring that micro-organisms reach the rhizosphere alive, even under the stressful conditions of an irrigation circuit.
PGPR Mechanisms: What Happens at the Root Surface
PGPR stands for Plant Growth-Promoting Rhizobacteria. These bacteria act through multiple simultaneous pathways: production of auxins (IAA) for root elongation, solubilization of inorganic phosphorus fixed in the substrate, secretion of siderophores for iron chelation, formation of a protective exopolysaccharide (EPS) biofilm on the root surface, secretion of enzymes useful for hydrolyzing cellulosic matter, and secretion of biosurfactants that facilitate bacterial movement and solubilize various substrates useful for rhizospheric bacteria.
Adding Éra Boost Pro or Éra N-Fix in Irrigation Water
When Éra Boost Pro or Éra N-Fix is introduced into the irrigation system, Bacillus spores reach the rhizosphere within hours. Upon contact with root exudates, they germinate and begin colonizing the root surface (J0). Within 7 to 10 days (S1), vegetative cells form a protective biofilm composed of exopolysaccharides (EPS) that occupies attachment sites before pathogens can establish. Between S2 and S3, PGPR mechanisms become fully active: auxin (IAA) production for root elongation, siderophore secretion for iron chelation, and active solubilization of inorganic phosphorus fixed in the substrate. The rhizospheric effect is maintained for 3 weeks after a single application in a commercial greenhouse setting.
Why a Consortium Rather Than a Single Strain?
No single strain simultaneously expresses all these mechanisms at optimal levels. Éra Boost Pro and Éra N-Fix are formulated as consortiums of complementary strains whose activities reinforce one another. This functional redundancy ensures complete rhizospheric coverage even when greenhouse or field conditions like pH, temperature, substrate type favor certain strains over others.
Éra Boost Pro and Éra N-Fix: Two Products, One Rhizospheric Logic
Éra Boost Pro is formulated for rhizospheric stimulation in greenhouse vegetable and horticultural production: phosphorus solubilization, IAA production, protective biofilm. Éra N-Fix adds atmospheric nitrogen fixation activity through Paenibacillus polymyxa strains, a rare capability in substrate-based greenhouse contexts and in the field. Both products share the same application logic: a single injection into the irrigation water is sufficient to initiate colonization.