Bacillus thuringiensis como controlador biológico de Brevicoryne brassicae en el cultivo de col (Brassica oleracea var. Capitata)

Bacillus are a well-known genus of bacteria that are characterized by others by the great resistance they present against acids, high temperatures, high pressure, bases and long storage times. B. thuringiensis is a bacterium that is located in soils located and characteristically produce protein crystals that exhibit insecticidal activity; these crystals are formed in the sporulation stage and are composed of toxins from the Cry and/or Cyt families, which once ingested by insects, these toxins are activated proteolytically. Research has determined that a single plasmid of B. thuringiensis is possible to host multiple variants of cry and cyt that in their combination determine the specificity of the host insect. Ingestion: In this step unlike other insecticides, this one must be ingested; because the proteins of B. thuringiensis act only before the previous ingestion of the insect and never through contact. Solubilization: This phase consists of the breakage of the crystals and the release of the proteins present in them. This phase is mainly produced by trypsins and chymotrypsins, the most abundant enzymes in the insect's intestinal fluids. Crossing the intestinal membrane: Once the toxins are activated, the peritrophic membrane of the intestine reduces the amount of toxins that can interact with intestinal cells, having an effect on the insect's final susceptibility to the toxin, which are capable of degrading chitin. This manages to generate an osmotic imbalance that is capable of leading to cell rupture. Through the lysis of the intestinal cell sepsis occurs, caused by all opportunistic bacteria and other pathogens in the food bolus, which produces the death of the insect

• Autor principal: López Gallardo, Adriana Katerine (author)
• Formato: bachelorThesis
• Publicado em: 2022
• Assuntos: Bacillus thuringiensis; Controlador biológico; Brevicoryne Brassicae; Brassica oleracea
• Acesso em linha: http://dspace.utb.edu.ec/handle/49000/13316