title: Microscopic analysis of a native Bacillus thuringiensis strain from Malaysia that produces exosporium-enclosed parasporal inclusion.
abstract: The current study focused on the microscopic studies of a native Bacillus thuringiensis strain isolated from Malaysia, Bt-S84-13a, that produced an unusual crystal type. Primary detection of parasporal inclusions using a phase contrast microscope presented one to two small crystal proteins in the sporulating cells of Bt-S84-13a. Compound light microscopic examination of autolysed Bt-S84-13a cells stained with 0.133% Coomassie Brilliant Blue showed two types of crystal morphology: small crystals independent of spores and spore-associated crystals. Surface structure analysis with a scanning electron microscope revealed spherical-like, coarse and wrinkled-looking crystal in Bt-S84-13a. A close-up observation of the crystal morphology using a transmission electron microscope also demonstrated two parasporal inclusions in Bt-S84-13a. One inclusion was deposited against the forespore and was in a shape of incomplete rectangular. Another smaller inclusion was developed within the exosporium and was rectangular in shape. However, the latter inclusion was found lack in another bacterial cell which was still in the early stages of sporulation. This unique crystal morphology may imply some biological potential in Bt-S84-13a.
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia.
authors.forename: Pui Fun
authors.initials: PF
authors.lastname: Chai
authors.affiliation: Department of Biotechnology, Faculty of Applied Sciences, AIMST University, 08100, Semeling, Kedah, Malaysia.
authors.forename: Xavier
authors.initials: X
authors.lastname: Rathinam
authors.affiliation: Department of Biotechnology, Faculty of Applied Sciences, AIMST University, 08100, Semeling, Kedah, Malaysia.
authors.forename: Maheswaran
authors.initials: M
authors.lastname: Solayappan
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia.
authors.forename: Amir Hamzah
authors.initials: AH
authors.lastname: Ahmad Ghazali
authors.affiliation: School of Biological Sciences, Universiti Sains Malaysia, 11800, Pulau Pinang, Malaysia sreeramanan@gmail.com.
authors.forename: Sreeramanan
authors.initials: S
authors.lastname: Subramaniam
mesh_terms: D001413:Bacillus thuringiensis / Q000502:physiology / Q000648:ultrastructure*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000648:ultrastructure; D003460:Crystallization; D004731:Endotoxins; D006460:Hemolysin Proteins / Q000648:ultrastructure; D008296:Malaysia; D008855:Microscopy, Electron, Scanning; D008858:Microscopy, Phase-Contrast; D013171:Spores, Bacterial / Q000648:ultrastructure
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis
keywords: Bacillus thuringiensis; crystal morphology; crystal protein; parasporal inclusion; spore-associated crystal