Producción de biosurfactantes lipopeptídicos por Bacillus spp. en fermentación en medios sólido y líquido
The lipopeptide biosurfactants produced by Bacillus, have applications in different fields of industry. Lipopeptides have been mainly carried out in submerged fermentation which presents foaming associated with biosurfactant production. Besides, some increase in medium viscosity is due to the produc...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2022 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:p5547r609 |
| Acceso en línea: | https://doi.org/10.24275/uami.p5547r609 |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Fermentación info:eu-repo/classification/LEM/Biosíntesis info:eu-repo/classification/LEM/Biosynthesis info:eu-repo/classification/LEM/Fermentation info:eu-repo/classification/cti/6 |
| Sumario: | The lipopeptide biosurfactants produced by Bacillus, have applications in different fields of industry. Lipopeptides have been mainly carried out in submerged fermentation which presents foaming associated with biosurfactant production. Besides, some increase in medium viscosity is due to the production of exopolysaccharides by some strains. Foaming and high viscosity decrease oxygen transfer, increasing the production costs and diminishing product concentration. On the other hand, solid-state fermentation does not present such problems and Reports of lipopeptide production in solid-state fermentation are scarce but satisfactory and have mostly used natural supports (non-inert material), agro-industrial residues, or complex culture media, which hinders recovery, purification, and analysis of the product. The aim of the work was to develop a bioprocess with higher LP production in solid-state fermentation with a defined medium adsorbed on an inert support such as polyurethane foam. The above facilitate the control of the bioprocess, recovery, analysis of the products, and comparison with submerged fermentation. In this way, identify and understand the relationship between secondary and primary metabolism and some limiting nutrients with the bioprocess. Part I of this work used Bacillus subtilis ATCC 6633 for the tests as improvement of the strain, selection of the most favorable solid support, and the effect of C/N on LP production. Polyurethane foam is the support that could allow the greatest lipopeptide production. The ammonium nitrate and C/N 17.1, was the most favorable condition for the bioprocess. For Part II, different strains were studied in solid and submerged fermentation, four wild and one mutant strain (unable to develop biofilm). The wild-type strains revealed a higher production of lipopeptides and biomass, glucose consumption, and a lower synthesis of primary metabolites in solid-state fermentation than in submerged. However, the mutant strain produced a slightly higher production of primary metabolites in solid fermentation than in submerged. The analysis of the carbon balance showed that the carbon flux is directed mainly to lipopeptides in solid-state fermentation, whereas, in submerged fermentation, it is directed to the production of primary metabolites. In the present work, a bioprocess is developed in solid-state fermentation with high lipopeptide production, mainly fengycin (2.7 g/L) and iturin (1.2 g/L) using a defined medium adsorbed on inert support by the Bacillus subtilis ATCC 21332. The concentrations reached are higher than those reported in the literature by wild strains. To the best of my knowledge, this is the first report that uses polyurethane foam in solid-state fermentation for lipopeptide production, facilitating the recovery and analysis of the product, as well as glucose and biomass. Furthermore, this is the first study to present the quantitative production of fengycin by solid fermentation. |
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