Biocontrol Science and Technology (2015) 25, 414-428

Elisangela Andrade Angelo, Gislayne Trindade Vilas-Bôas, Raúl Jorge Hernan Castro-Gómez and José Lopes (2015)
Utilisation of response surface methodology to optimise the culture medium for Bacillus thuringiensis subsp. israelensis
Biocontrol Science and Technology 25 (4), 414-428
Abstract: Bacillus thuringiensis israelensis (Bti) is a sporulating Gram-positive bacterium that produces protein crystals with insecticide activity against Diptera. The aim of the present work was to optimise the culture medium for this bacterium, based on mathematical and statistical concepts (factorial designs and response surface methodology). The variables studied were carbon and nitrogen source concentrations. The main response analysed was toxicity, evaluated by means of bioassay with Aedes aegypti. The nutrient sources were first selected and then optimised. Ground Bombyx mori pupae, ammonium sulphate and glucose were the most suitable sources of organic nitrogen, inorganic nitrogen and organic carbon, respectively. The toxicity of optimised medium (LC₅₀ = 0.703 ppm, v/v) was higher than that the medium used as reference (LC₅₀ = 3.01 ppm, v/v), which is commonly used in the laboratory culture of Bti. Besides, the optimised medium showed a cost 7.36 times less than that of an alternative medium, based on soybean flour and sugarcane molasses. Factorial design and response surface methodology were effective methods for culture medium optimisation. The results will contribute to the development of local production and utilisation of agroindustrial waste locally.
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Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
rearing/culturing/mass production

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Aedes aegypti
Bacillus thuringiensis var. israelensis (entomopathogen)	Aedes aegypti