Production of concentrates of bacterial bio-insecticide Bacillus thuringiensis var. israelensis by flocculation/sedimentation

• Published in: Acta tropica Vol. 107; no. 2; pp. 134 - 138
• Main Authors: Luna-Finkler, Christine Lamenha, Finkler, Leandro
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-08-2008; Elsevier
• Subjects: Aedes - growth & development; Aedes - microbiology; Aedes aegypti; Animals; Bacillus thuringiensis; Bacillus thuringiensis - growth & development; Bacillus thuringiensis var. israelensis; Bio-insecticide; Biological and medical sciences; Biotechnology - methods; Centrifugation - methods; Culture Media; Flocculation; General aspects; Insecticides; Larva - microbiology; Medical sciences; Pest Control, Biological; Sedimentation; France; Provence Alpes Côte d'Azur; Europe; Var; Bacillus thuringiensis var. israelensis; Sedimentation; Flocculation; Bio-insecticide; Infection; Insecticide; Bacillales; Sédimentation,Flocculation,Bacillus thuringiensis var. israelensis,Bio-insecticide; Bacillus thuringiensis; Pesticides; Production; Bacteriosis; Bacteria; Tropical medicine; Bacillaceae
• ISSN: 0001-706X; 1873-6254
• DOI: 10.1016/j.actatropica.2008.05.008

Flocculation/sedimentation of
Bacillus thuringiensis var.
israelensis (Bti) using flocculating agents has been studied. Batch cell production was performed in an agitated tank, and the flocculation assays were carried out in jar tests. Flocculent suspensions were characterized based on diameter of flocs and density. The best results were obtained with CaCl
2·2H
2O, FeCl
3·6H
2O, Al
2(SO
4)
3 and tannin, with optimal flocculation concentrations of 2500, 2500, 3500 and 1000
mg
l
−1, respectively. Thickening of the flocculent suspensions was investigated, leading to determination of the capacity curves of the settler. Bioassays against
Aedes aegypti larvae demonstrated excellent results in insect control.