Production of biostimulants from okara through enzymatic hydrolisis and fermentation with Bacillus licheniformis. Comparative effect on soil biological properties.

In this work okara (OK), a by-product of soy milk manufacturing, is submitted to an enzymatic hydrolysis and a fermentative process to produce different soil biostimulants (BS): EH, hydrolysate obtained by the enzymatic process; FHEB, fermentation broth with Bacillus licheniformis and the enzymes se...

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Detalles Bibliográficos
Autores: Orts, Ángel, Tejada, Manuel, Parrado, Juan, Paneque, Patricia, García, Carlos, Hernández, Teresa, Gómez Parrales, Isidoro Ángel
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2018
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/154945
Acceso en línea:https://hdl.handle.net/11441/154945
https://doi.org/10.1080/09593330.2018.1436596
Access Level:acceso abierto
Palabra clave:KEYWORDS Okara
soil biostimulation
enzymatic hydrolysis
Bacillus licheniformis
fermentation
Descripción
Sumario:In this work okara (OK), a by-product of soy milk manufacturing, is submitted to an enzymatic hydrolysis and a fermentative process to produce different soil biostimulants (BS): EH, hydrolysate obtained by the enzymatic process; FHEB, fermentation broth with Bacillus licheniformis and the enzymes secreted during the fermentation; FHE, fermentation broth without bacteria and FH, the FHE hydrolysate in which enzymes were denatured. Enzymatic hydrolysates showed a different chemical composition compared with fermented hydrolysates and OK. It had a higher protein concentration as well as C, P and K. The proteins of OK were converted into peptides with a lower molecular weight, the fermented hydrolysates being those with the lowest molecular weight profile. The influences of hydrolysates and OK were tested in soil, finding that β-glucosidase, phosphatase and dehydrogenase activities were stimulated by every treatment. However, it was observed that EH produced a greater stimulation of dehydrogenase and phosphatase than both OK and fermented BS. The bacterial and fungal phospholipid fatty acids were also higher in soils amended with BS than those of the control and soils with OK. It has also been found that β-glucosidase, phosphatase and microbial biomass were dose-dependent in every treatment, but dehydrogenase only was dose-dependent in EH and OK treatments.