EFFECTS OF CHITOSAN NANO-MICROPARTICLES ON SOIL MICROBIOTA

MESAS, FLORENCIA; TORRES NICOLINI, A.; BILESKY-JOSE, NATALIA; DE LIMA, RENATA; FERNADES FRACETO, LEONARDO; ÁLVAREZ, VERA A; CASALONGUE, CLAUDIA; MENDIETA, J.R.; TERRILE, M.C.

Mar del Plata

Congreso; XVIII Congreso de la Sociedad Argentina de Microbiologia General; 2023

Sociedad Argentina de Microbiologia General

Due to the rising global population and increased need for food over the past few years, agrochemical use has significantly expanded. Therefore, new agricultural practices aim to achieve the sustainability of agricultural production by reducing the doses of these toxic compounds that are harmful to human health and the environment. Chitosan-based nano-microparticles (CS-NP/MP) have emerged as a promising alternative to replace them. Toxicology testing is crucial, however, because nanomaterials have a large surface area and might interact with biological membranes and have adverse effects. In this study, we evaluate the in vitro effects on soil microbiota of three CS-NP/MP with different physicochemical properties, designed as CS-NP, CS-MP1, and CS-MP2. First, we quantified colony-forming units to determine the number of fungus and bacteria present in the soil microbiota. We did not detect any significant changes in the analyzed groups of microorganisms in the control soil. Then, we studied the changes in the amount and distribution of bacteria involved in nitrogen cycling by analyzing different genes by q-PCR due to the importance of nitrogen fixation to make the soil fertile. Soil exposed to CS-MP2 showed the highest difference in the quantity and distribution of bacteria after 45 days, with a decline in the proportion of bacteria that fix nitrogen and an increase in those that denitrify nitrogen. For CS-NP and CS-MP1, however, we did not find significant variations from the control. According to the findings, the examined soil microorganisms exhibited better resistance to the CS-NP/MP. We explain our results in view of the biocompatibility and potential applications of CS-NP/MP as a novel form of biomaterial in contemporary agriculture.