Postbiotics vs Probiotics: The Difference

An important distinction within microbial biostimulants is:

• Probiotics = living bacteria or fungi (e.g., Bacillus, Trichoderma)
• Postbiotics = metabolites and components derived from microbes

Postbiotics offer advantages in terms of shelf life, formulation, and tank mix stability.

Why Are Postbiotics Interesting for Agriculture?

Postbiotics are attractive because they can provide multifunctional effects without the limitations of living microorganisms. Key benefits include:

• high stability in liquid formulations
• no dependence on soil colonization
• rapid direct plant response
• broad applicability in fertigation and foliar application

Microbial Metabolites as Biostimulant Signals

Microbes produce a wide spectrum of metabolites that steer plant physiology, such as:

• lipopeptides (e.g., surfactin)
• siderophores for micronutrient mobility
• polysaccharide fragments as elicitors
• organic acids and signaling molecules

These molecules activate stress responses, root growth, and uptake efficiency.

ISR and Plant Resilience via Postbiotics

A core mechanism of postbiotic biostimulants is the activation of Induced Systemic Resistance (ISR). Postbiotic elicitors “prime” the plant for faster defense reactions.

This results in:

• increased phenol production
• stronger cell wall defense
• higher tolerance against pathogens
• more stress adaptation under field conditions

Abiotic Stress Mitigation and Priming

Postbiotics also support tolerance against drought, salt stress, and heat by:

• faster antioxidant response
• improved osmoregulation
• higher root continuity
• quicker recovery after stress peaks

This makes postbiotics fit perfectly within plant stress mitigation strategies.

Synergy with Amino Acids and Fulvic Acid

Postbiotic formulations are often combined with amino acids and fulvic acid. Free amino acids provide a complete profile of all 20 amino acids, essential for enzymatic rebuilding and recovery.

Additionally, amino acids support the citric acid cycle (Krebs cycle), releasing ATP for transport and stress recovery.

Fulvic acid simultaneously enhances micronutrient mobility through natural chelation, supporting photosynthesis and vitality.

Application and Commercial Value

For formulators and purchasers, postbiotics are interesting as a new generation of raw materials because they:

• are more stable than living inoculants
• are broadly compatible in tank mix systems
• provide rapid functional effects
• are suitable for sustainable crop inputs

Thus, postbiotics represent a rapidly growing segment within innovative biostimulant raw materials.

Overview: Postbiotics as a Biostimulant Platform