As part of the BioBOOST project, the Laboratory of Biochemical Engineering and Environmental Technology conducted a series of experiments and analyses aimed at evaluating different species of microalgae and cyanobacteria as potential biofertilizers and biostimulants for agricultural applications.
A total of eight different strains and cultures were studied, including Arthrospira platensis, Nannochloris sp., Chlorella sp., Chlorella vulgaris, Acutodesmus obliquus, Parachlorella kessleri, Chlorella vacuolata, as well as a mixed microalgal culture.
The species were grown under autotrophic conditions in optimal culture media and subsequently evaluated through plant bioassays and physicochemical analyses. The study focused both on investigating their biostimulant and soil-improving effects and on determining their content of essential nutrients, such as nitrogen (N), phosphorus (P), and potassium (K), which are essential for plant growth and nutrition.
Figure 1: Cultivation of 8 species of microalgae under controlled temperature and light conditions.
Figure 2: Testing of whole-plant biomass from roving plants, as well as biomass supernatants from the 8 species of microalgae and cyanobacteria, to detect and quantify the plant hormone auxin using mung bean plants.
Figure 3: Germination index tests on cucumber seeds to monitor their growth in comparison with control samples (treated with distilled water), in order to evaluate the growth-improving effect of crop biomass.
Figure 4: Test of cucumber cotyledons expansion when immersed in the biomass and supernatants of each species, as an indicator for the detection and quantification of the phytohormone cytokinin.