title: Mathematical relationships between spore concentrations, delta-endotoxin levels, and entomotoxicity of Bacillus thuringiensis preparations produced in different fermentation media.
abstract: Mathematic relationships between spore concentrations, delta-endotoxin concentrations and entomotoxicity (Tx) of Bacillus thuringiensis var. kurstaki HD-1 (Btk HD-1) preparations produced in six different media were analysed. The relationship between delta-endotoxin and spore concentration and SpTx-spore (specific Tx per 1000 spore) and spore concentration produced in the different media (starch industry wastewater (SIW) with total solids (TS) concentration of 15g/L, SIW with TS of 30g/L, SIW supplemented with 0.2% (w/v) colloidal chitin, SIW supplemented with 1.25% (w/v) cornstarch and 0.2% (v/v) Tween 80, secondary sludge, and semi-synthetic medium) strictly followed the Power law. Tx and delta endotoxin concentration followed the exponential relation whereas a definite relation between Tx and spore concentration could not be established. Spore and delta-endotoxin produced at the early time (12h) during fermentation might be more toxic than those produced during latter period of fermentation irrespective of media used. Tx and delta-endotoxin concentration exhibited a semi-log linear relationship. Based on these findings, delta-endotoxin concentration can be determined rapidly to monitor the progress of the biopesticide production process.
authors.affiliation: INRS-ETE, Université du Québec, 490 rue de la Courrone, Québec, Canada G1K 9A9.
authors.forename: Khanh Dang
authors.initials: KD
authors.lastname: Vu
authors.forename: R D
authors.initials: RD
authors.lastname: Tyagi
authors.forename: R Y
authors.initials: RY
authors.lastname: Surampalli
authors.forename: J R
authors.initials: JR
authors.lastname: Valéro
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000378:metabolism* / Q000633:toxicity*; D003470:Culture Media / Q000494:pharmacology*; D004731:Endotoxins / Q000378:metabolism* / Q000633:toxicity*; D005285:Fermentation / Q000187:drug effects; D006460:Hemolysin Proteins / Q000378:metabolism* / Q000633:toxicity*; D009036:Moths / Q000187:drug effects*; D012722:Sewage / Q000382:microbiology; D013171:Spores, Bacterial / Q000187:drug effects; D018675:Toxicity Tests
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D003470:Culture Media; D004731:Endotoxins; D006460:Hemolysin Proteins; D012722:Sewage; C030956:insecticidal crystal protein, Bacillus Thuringiensis