Nitrogen source-dependent biofilm formation in A.Brasilense as an approcach to effective biostimulant formulas
Consultable a partir de
2025-10-01
Fecha
2023Versión
Acceso embargado 2 años / 2 urteko bahitura
Tipo
Trabajo Fin de Máster/Master Amaierako Lana
Impacto
|
nodoi-noplumx
|
Resumen
In a global growing population, the need to raise productivity and resources in an efficient
manner with minimal environmental impact has become a main challenge to achieve in the agricultural
sector. Diazotrophic A.brasilense is known for their ability to fix-nitrogen and promote plant growth,
being a promising tool for agriculture as plant biostimulant (PB). Although the market of these prod ...
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In a global growing population, the need to raise productivity and resources in an efficient
manner with minimal environmental impact has become a main challenge to achieve in the agricultural
sector. Diazotrophic A.brasilense is known for their ability to fix-nitrogen and promote plant growth,
being a promising tool for agriculture as plant biostimulant (PB). Although the market of these products
is flourishing, many biostimulants still result in variable outcomes and therefore low reliability. For that
reason, it is of interest to know which environment favors its growth and survival, and is more efficient
as plant growth promoter bacteria (PGPB). As growing bacteria is commonly carried out in rich medium
to ensure rapid replication, the present study wanted to take into account environments that bacteria
would find after the application of biostimulant formulas. Thinking that plant biostimulants will most
likely be compensated with inorganic fertilizers and applied in many areas where soils are poor in
nutrients, the following nitrogen sources were used: nitrate (NO3
-
), ammonium (NH4
+
), atmospheric
nitrogen (N2) and rich medium (LB). In addition, many of these biostimulants use model strains as they
are widely studied and available on the market. However, it is known that wild strains isolated from
ecosystems where environmental conditions are not ideal, are better adapted for survival and therefore
are of great interest for a successful viability of biostimulant formulas. For that reason, A.brasilense
model strains such as SP7 and SP245 and isolated strains such as 29145 and ARG2 were used in this
study. Bacterial growth (OD600), biofilm biomass (OD550), biofilm patterns and early stages of biofilm
formation as well as their survival strategies and their carbon and nitrogen usage for each strain in each
nitrogen scenario was analyzed. Overall results suggest that isolated strains perform better than model
strains. In particular, ARG2 strain shows great fitness. Moreover, this strain tends to form cysts in all
studied medium compared to other strains. Encysting is a survival strategy that A.brasilense can adopt
to face environmental stress. Taking into account that such structures are capable of fixing nitrogen
under aerobic conditions, it would be of great interest the research of their potential for future
biostimulant formulas. [--]
Titulación
Máster Universitario en Agrobiología Ambiental /
Unibertsitate Masterra Ingurumen Agrobiologian