title: Small microcapsules of crystal proteins and spores of Bacillus thuringiensis by an emulsification/internal gelation method.
abstract: This paper describes a microencapsulation process of a spore crystal aggregate produced by Bacillus thuringiensis var. kurstaki HD-1. The methodology is based on the emulsification/internal gelation method, and was implemented to produce microcapsules of small diameter (< 10 μm) with the capacity to protect the spore crystal aggregate from extreme ultraviolet radiation. The diameter of microcapsules was in the range of 3.1 ± 0.2-6.8 ± 0.4 μm, which is considered adequate for biological control purposes. The protective effect of the alginate coat was verified by the remaining 60 ± 2% and 40 ± 1% of spore viability and protein activity, respectively, after UV-B radiation of 236 J, and with bioassays with Spodoptera frugiperda. It is expected that the protective effect of the alginate coat will improve the effectiveness of the Bt-HD1 formulated as small diameter microcapsules, and their yield, once they are released into the environment, will also be improved.
authors.affiliation: Departamento de Biotecnología y Bioingeniería, CINVESTAV, Av. Instituto Politécnico Nacional, 2508. CP. 07360, P.O. Box 14-740, Col. San Pedro Zacatenco D.F., 07000, Mexico.
authors.forename: Karina
authors.initials: K
authors.lastname: García-Gutiérrez
authors.forename: Héctor M
authors.initials: HM
authors.lastname: Poggi-Varaldo
authors.forename: Héctor M
authors.initials: HM
authors.lastname: Poggy-Varaldo
authors.forename: Fernando
authors.initials: F
authors.lastname: Esparza-García
authors.forename: Jorge
authors.initials: J
authors.lastname: Ibarra-Rendón
authors.forename: Josefina
authors.initials: J
authors.lastname: Barrera-Cortés
mesh_terms: D000464:Alginates / Q000737:chemistry; D000818:Animals; D001413:Bacillus thuringiensis / Q000737:chemistry*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000633:toxicity*; D001681:Biological Assay; D002214:Capsules; D004655:Emulsions / Q000737:chemistry; D004731:Endotoxins / Q000633:toxicity*; D005780:Gelatin / Q000737:chemistry; D020723:Glucuronic Acid / Q000737:chemistry; D006460:Hemolysin Proteins / Q000633:toxicity*; D006603:Hexuronic Acids / Q000737:chemistry; D010572:Pest Control, Biological; D018411:Spodoptera / Q000187:drug effects* / Q000382:microbiology; D013171:Spores, Bacterial / Q000378:metabolism / Q000528:radiation effects
chemical_list: D000464:Alginates; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D002214:Capsules; D004655:Emulsions; D004731:Endotoxins; D006460:Hemolysin Proteins; D006603:Hexuronic Acids; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D020723:Glucuronic Acid; D005780:Gelatin