title: The Exosporium ofBacillus megateriumQM B1551 Is Permeable to the Red Fluorescence Protein of the CoralDiscosomasp.
abstract: Bacterial spores spontaneously interact and tightly bind heterologous proteins. A variety of antigens and enzymes have been efficiently displayed on spores ofBacillus subtilis, the model system for spore formers. Adsorption onB. subtilisspores has then been proposed as a non-recombinant approach for the development of mucosal vaccine/drug delivery vehicles, biocatalysts, bioremediation, and diagnostic tools. We used spores ofB. megateriumQM B1551 to evaluate their efficiency as an adsorption platform. Spores ofB. megateriumare significantly larger than those ofB. subtilisand of otherBacillusspecies and are surrounded by the exosporium, an outermost surface layer present only in someBacillusspecies and lacking inB. subtilis.Strain QM B1551 ofB. megateriumand a derivative strain totally lacking the exosporium were used to localize the adsorbed monomeric Red Fluorescent Protein (mRFP) of the coralDiscosomasp., used as a model heterologous protein. Our results indicate that spores ofB. megateriumadsorb mRFP more efficiently thanB. subtilisspores, that the exosporium is essential for mRFP adsorption, and that most of the adsorbed mRFP molecules are not exposed on the spore surface but rather localized in the space between the outer coat and the exosporium.
authors.affiliation: Department of Biology, University of Naples Federico II Naples, Italy.
authors.forename: Mariamichela
authors.initials: M
authors.lastname: Lanzilli
authors.affiliation: Department of Biology, University of Naples Federico II Naples, Italy.
authors.forename: Giuliana
authors.initials: G
authors.lastname: Donadio
authors.affiliation: Department of Biology, University of Naples Federico II Naples, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Addevico
authors.affiliation: Department of Biology, University of Naples Federico II Naples, Italy.
authors.forename: Anella
authors.initials: A
authors.lastname: Saggese
authors.affiliation: Department of Biology, University of Naples Federico II Naples, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Cangiano
authors.affiliation: Department of Biology, University of Naples Federico II Naples, Italy.
authors.forename: Loredana
authors.initials: L
authors.lastname: Baccigalupi
authors.affiliation: Department of Chemical Engineering and Biotechnology, University of Cambridge Cambridge, UK.
authors.forename: Graham
authors.initials: G
authors.lastname: Christie
authors.affiliation: Department of Biology, University of Naples Federico II Naples, Italy.
authors.forename: Ezio
authors.initials: E
authors.lastname: Ricca
authors.affiliation: Department of Biology, University of Naples Federico II Naples, Italy.
authors.forename: Rachele
authors.initials: R
authors.lastname: Isticato
keywords: Bacillus megaterium; exosporium; protein delivery; spores; surface display