Rhizobia exopolysaccharides: promising biopolymers for use in the formulation of plant inoculants.

Autor: Palhares Farias T; Departamento de Ciência Do Solo, Universidade Federal de Lavras (UFLA), Caixa Postal 3037, CEP 37200-900, Lavras, MG, Brazil.; Laboratório de Microbiologia Do Solo E Biotecnologia/DDE, IFMA, Campus São Luís - Maracanã, CEP 65095-460, São Luís, MA, Brazil., de Melo Castro E; Universidade Federal de Lavras, Caixa Postal 3037, CEP 37200-900, Lavras, MG, Brazil., Marucci Pereira Tangerina M; Instituto de Biociências, UNESP, Campus do Litoral Paulista, CEP 11330-900, São Vincente - SP, Brazil., Quintino da Rocha C; Departamento de Química da, Universidade Federal Do Maranhão, Campus Universitário Dom Delgado, 1966, CEP 65080-040, São Luís, MA, Brazil., Brito Bezerra CW; Departamento de Química da, Universidade Federal Do Maranhão, Campus Universitário Dom Delgado, 1966, CEP 65080-040, São Luís, MA, Brazil., de Souza Moreira FM; Departamento de Ciência Do Solo da, Universidade Federal de Lavras, Campus Universitário, Caixa Postal 3037, CEP 37200-900, Lavras, MG, Brazil. fmoreira@ufla.br.
Jazyk: angličtina
Zdroj: Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology] [Braz J Microbiol] 2022 Dec; Vol. 53 (4), pp. 1843-1856. Date of Electronic Publication: 2022 Sep 15.
DOI: 10.1007/s42770-022-00824-z
Abstrakt: Inoculants with beneficial microorganisms comprise both selected strains and carriers that ensure a favorable microenvironment for cell survival and stability. Formulations of inoculants using synthetic polymers as carriers are common. However, only a few studies are available in the literature regarding the formulation of inoculants using natural biomolecules as carriers. Exopolysaccharides (EPS) are biomolecules produced by a vast array of microbial species, including symbiotic nitrogen-fixing bacteria, commonly known as rhizobia. EPS perform several functions, such as the protection against the deleterious effects of diverse environmental soil stresses. Two Rhizobium tropici strains and one Paraburkholderia strain were selected after semiquantitative analysis by scanning electron microscopy (SEM) of their EPS production in liquid YMA medium. Their EPS were characterized through a series of analytical techniques, aiming at their use in the formulation of plant inoculants. In addition, the effect of the carbon source on EPS yield was evaluated. Multi-stage fragmentation analysis showed the presence of xylose, glucose, galactose, galacturonic acid, and glucuronic acid in EPS chemical composition, which was confirmed by FT-IR spectra and 13 C NMR spectroscopy. Thermal stability (thermogravimetric) was close to 270 °C and viscosity ranged from 120 to 1053.3 mPa.s. Surface morphology (SEM) was rough and irregular, with a cross-linked spongy matrix, which, together with the hydrophilic functional groups, confers water holding capacity. The present study showed that the three EPS have potential as microorganism carriers for formulation of microbial inoculants to be applied in plants.
(© 2022. The Author(s) under exclusive licence to Sociedade Brasileira de Microbiologia.)
Databáze: MEDLINE
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