Identification and effect of ozone and ultrasound pretreatments on Desmodesmus sp. and Tetradesmus obliquus proteins
Either ozone or ultrasound pretreatment was applied to identify and evaluate their effect over the protein fraction of Desmodesmus sp. and Tetradesmus obliquus biomass cultivated in wastewater. Studies of SDS-PAGE, protein solubility, sulfhydryl and disulphide bond contents, and DSC were performed t...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2021 |
| País: | España |
| Institución: | Universidad de Sevilla (US) |
| Repositorio: | idUS. Depósito de Investigación de la Universidad de Sevilla |
| OAI Identifier: | oai:idus.us.es:11441/173335 |
| Acceso en línea: | https://hdl.handle.net/11441/173335 https://doi.org/10.1016/j.algal.2021.102514 |
| Access Level: | acceso abierto |
| Palabra clave: | Ozonation Ultrasonication Proteins identification Desmodesmus sp. Tetradesmus obliquus |
| Sumario: | Either ozone or ultrasound pretreatment was applied to identify and evaluate their effect over the protein fraction of Desmodesmus sp. and Tetradesmus obliquus biomass cultivated in wastewater. Studies of SDS-PAGE, protein solubility, sulfhydryl and disulphide bond contents, and DSC were performed to evaluate the effect of each pretreatment on abundance, structure, and thermal properties of the protein concentrate obtained. Seven proteins were identified in Desmodesmus sp. biomass, while nine proteins were identified in Tetradesmus obliquus. The proteins identified may give a high add-value to microalgae biomass because they can find important applications in agricultural, food, and biomedical areas. On the other hand, the effect of pretreatment on these microalgal proteins mainly depends on protein structure. Desmodesmus sp. proteins showed a content of S-S groups an order of magnitude higher than Tetradesmus obliquus. This results in a higher glass transition temperature (Tg) for Desmodesmus sp. proteins (249 °C) than for Tetradesmus obliquus proteins (188 °C). On the contrary, the Tetradesmus obliquus native structure proteins tend towards cross-linking and protein-protein aggregation, as their primary structure has a high content of Methionine, Tyrosine, Tryptophan, Histidine, and Phenylalanine. Either ozone or ultrasound pretreatment, induces a Tg reduction in both Tetradesmus obliquus and Desmodesmus sp. proteins, however, this reduction is especially remarkable for Desmodesmus sp. proteins (drop in Tg of about 80 °C). The results showed that proteins in Desmodesmus sp. and Tetradesmus obliquus are highly resistant to pretreatment due to the nature of their biochemical structures which imply an excellent quality for protein valorisation, even after application of highly disruptive pretreatments. |
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