EUBCE 2026 - Michael KORNAROS - Screening of Microalgal Species for Biostimulant and Biofertilizer Potential

Screening of Microalgal Species for Biostimulant and Biofertilizer Potential

Short Introductive summary

Microalgae are gaining scientific interest as sustainable alternatives to chemical fertilizers due to their rich nutrient and bioactive compound profiles. This study screened eight species—Arthrospira platensis, Nannochloris sp., Chlorella sp., Chlorella vulgaris, Chlorella vacuolata, Acutodesmus obliquus, Parachlorella kessleri, and a mixed culture—evaluating their biostimulant and biofertilizer potential under autotrophic conditions. Biomass concentrations ranged from 0.57 to 1.30 g L?¹, with the mixed culture yielding the most. Plant bioassays (assessing germination and phytohormone-like activity) and NPK analysis revealed strong species- and concentration-dependent effects. Chlorella strains significantly enhanced rooting (up to a 180% increase over the control) and showed high nitrogen content (up to 8.8% w/w). Conversely, A. platensis and Nannochloris sp. displayed inhibitory effects, suggesting possible phytotoxicity. Whole cultures consistently outperformed supernatants, indicating the main bioactive compounds are primarily intracellular. This study identifies promising microalgae species to help optimize sustainable agriculture and reduce reliance on synthetic fertilizers.

E. Sventzouri, University of Patras, GREECE
E. Pagkaki, University of Patras, GREECE
S. Zerveas, Institute of Technology of Agricultural Products, Lykovrysi, GREECE
G. Markou, Institute of Technology of Agricultural Products, Lykovrysi, GREECE
M. Kornaros, University of Patras, GREECE