BIOCOMPATIBILITY ASSESSMENT OF A NUTRIENT LOADED PICKERING EMULSION USING BENEFICIAL AGRICULTURAL MICROORGANISMS

Abstract

The biological compatibility of a nutrient-loaded Pickering emulsion was evaluated using three complementary biochemical assays: the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, the neutral red uptake (NRU) assay, and the lactate dehydrogenase (LDH) assay. The assessment involved agriculturally beneficial microorganisms, including Rhizobium and zinc-solubilizing bacteria (ZSB). The MTT assay showed that microbial viability remained above 94% in both Rhizobium and ZSB, even at a formulation concentration of 1600 ppm. Similarly, the NRU assay indicated high viability at 1200 ppm, with values of 95.6% in Rhizobium and 94.8% in ZSB. In contrast, LDH activity increased with formulation concentration, indicating a concentration associated increase in membrane-related cellular stress. Nevertheless, the high viability observed in the MTT and NRU assays suggests that the formulation did not substantially reduce microbial viability under the tested conditions. These results provide preliminary evidence that the developed Pickering emulsion is compatible with agriculturally beneficial microorganisms within the tested concentration range. However, further long-term and soil-based studies are required to establish its environmental safety.