Desarrollo de una emulsión W/O para un agente biocontrolador Bacillus velezensis UA2208
The success of the strategies used for biological control depends mainly on the antagonistic activity of the microorganism and the type of formulation in which it is incorporated for soil foliar application. However, in developing countries such as Colombia, microbial inoculants are developed withou...
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| Tipo de recurso: | tesis de maestría |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2020 |
| País: | Colombia |
| Institución: | Universidad Nacional de Colombia |
| Repositorio: | Repositorio UN |
| Idioma: | español |
| OAI Identifier: | oai:repositorio.unal.edu.co:unal/77791 |
| Acceso en línea: | https://repositorio.unal.edu.co/handle/unal/77791 |
| Access Level: | acceso abierto |
| Palabra clave: | 660 - Ingeniería química Biocontrol Bacillus velezensis Bioformulación Emulsión W/O Bacillus spp Control de plagas spray retention Bioformulation Emulsion W/O |
| Sumario: | The success of the strategies used for biological control depends mainly on the antagonistic activity of the microorganism and the type of formulation in which it is incorporated for soil foliar application. However, in developing countries such as Colombia, microbial inoculants are developed without technologies that make possible higher quality. Among the main challenges of bioformulates are physicochemical stability, the viability of microorganisms during storage and application, and their contact with the target surface. Based on the above, taking into account that aerobic endospore-forming bacteria (BAFE) have a high potential for commercial formulation, the present work aimed to develop an emulsion W/O ( Water in Oil) encapsulating Bacillus velezensis UA2208 spores suspended in sporulation medium. For this, five vegetable oils and one mineral, two emulsification systems and variations in temperature were tested for their ability to produce emulsions with colloidal and biological stability. From there, for the selected formulation the antagonistic activity in vitro was evaluated and a microscopic study of the phenomena of wettability and retention of the formulation on leaf surfaces was performed. First, the encapsulation of spores suspended in sporulation medium in a W / O emulsion was achieved using a medium energy system and as an oil phase sunflower oil containing 14% Tween 80 and Span 80 (HLB = 6). This formulation presented together the best colloidal and biological characteristics. The emulsion is characterized as a polydispersed system with an average particle size of 18.6 µm and a viscosity of 99.40 mPa*s and 35% separed phase at 13 days. The viability of the microorganism in the modified emulsion for 70 days was maintained for more than 50% and stabilized. With the selected formulation, in vitro tests of doses of 1, 5 and 10 ml / L of the emulsion demonstrated that the antagonistic activity against C. gloeosporioide and B. cinerea is maintained. Likewise, these doses evaluated on different surfaces showed that the addition of the concentrated formulation and in a concentration of 10 ml / L have a high capacity to reduce the contact angle and increase the probability of adhesion of the bioformulation to the leaf surface. In general, the formulation of Bacillus velezensis spores in W / O emulsions not only improves the viability and behavior of the microorganism in storage, but also gives it advantages in the application on different leaf surfaces |
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