title: Germinant generation from δ-endotoxin of Bacillus thuringiensis strain 1.1.
abstract: The novel finding of this study is that the δ-endotoxin present in the spore coat of Bacillus thuringiensis strain 1.1 (Bt1.1), plays a central role in spore germination by generation of germinant via its β-glucosidase activity and is based on the following: (i) the crystals of Bt1.1 consist of the 140 kDa δ-endotoxin which exhibits β-glucosidase enzymatic activity. Besides crystals, δ-endotoxin is also located in the spore coat and at this site displays β-glucosidase activity, resulting in glucose production; (ii) glucose is an efficient germinant of both Bt1.1 and acrystalliferous Bt4.1 strain; (iii) substrates of β-glucosidase can activate the germination of Bt1.1 spores, but not those of the acrystalliferous Bt4.1 sister strain that do not contain the 140 kDa δ-endotoxin; (iv) Reduction or enhancement of enzymatic activity of δ-endotoxin, results in retardation or acceleration of germination and outgrowth, respectively. Bt1.1 cells secrete a 60 kDa polypeptide which displays β-glucosidase activity as indicated by zymogram analysis and which is immunologically related to the 140 kDa δ-endotoxin.
authors.affiliation: Department of Genetics, Development and Molecular Biology, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Papalazaridou
authors.forename: Eirini
authors.initials: E
authors.lastname: Kanata
authors.forename: Afroditi
authors.initials: A
authors.lastname: Sivropoulou
mesh_terms: D001413:Bacillus thuringiensis / Q000166:cytology / Q000378:metabolism*; D004731:Endotoxins / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D013171:Spores, Bacterial / Q000166:cytology* / Q000378:metabolism
chemical_list: D004731:Endotoxins; D005947:Glucose