This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Google Scholar Articles by Jordal, P. B. Articles by Otzen, D. E. PubMed PubMed Citation Articles by Jordal, P. B. Articles by Otzen, D. E. Agricola Articles by Jordal, P. B. Articles by Otzen, D. E.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, June 2009, p. 4101-4110, Vol. 75, No. 12
0099-2240/09/$08.00+0     doi:10.1128/AEM.02107-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.

Widespread Abundance of Functional Bacterial Amyloid in Mycolata and Other Gram-Positive Bacteria

Peter Bruun Jordal,^1,2 Morten Simonsen Dueholm,^1,2 Poul Larsen,² Steen Vang Petersen,¹ Jan Johannes Enghild,¹ Gunna Christiansen,³ Peter Højrup,⁴ Per Halkjær Nielsen,^2* and Daniel Erik Otzen^1,2*

Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology, University of Aarhus, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark,¹ Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark,² Institute of Medical Microbiology and Immunology, Bartholin Building, University of Aarhus, DK-8000 Aarhus C, Denmark,³ Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark⁴

Received 3 September 2008/ Accepted 16 April 2009

Until recently, extracellular functional bacterial amyloid (FuBA) has been detected and characterized in only a few bacterial species, including Escherichia coli, Salmonella, and the gram-positive organism Streptomyces coelicolor. Here we probed gram-positive bacteria with conformationally specific antibodies and revealed the existence of FuBA in 12 of 14 examined mycolata species, as well as six other distantly related species examined belonging to the phyla Actinobacteria and Firmicutes. Most of the bacteria produced extracellular fimbriae, sometimes copious amounts of them, and in two cases large extracellular fibrils were also produced. In three cases, FuBA was revealed only after extensive removal of extracellular material by saponification, indicating that there is integrated attachment within the cellular envelope. Spores of species in the genera Streptomyces, Bacillus, and Nocardia were all coated with amyloids. FuBA was purified from Gordonia amarae (from the cell envelope) and Geodermatophilus obscurus, and they had the morphology, tinctorial properties, and β-rich structure typical of amyloid. The presence of approximately 9-nm-wide amyloids in the cell envelope of G. amarae was visualized by transmission electron microscopy analysis. We conclude that amyloid is widespread among gram-positive bacteria and may in many species constitute a hitherto overlooked integral part of the spore and the cellular envelope.

---

* Corresponding author. Mailing address for Daniel Erik Otzen: iNANO, Department of Molecular Biology, University of Aarhus, Gustav Wieds Vej 10C, DK-8000 Aarhus C, Denmark. Phone: 45 89 42 50 46. Fax: 45 86 12 31 78. E-mail: dao{at}inano.dk. Mailing address for Per Halkjær Nielsen: Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Sohngaardsholmsvej 49, DK-9000 Aalborg, Denmark. Phone: 45 99408503. Fax: 45 9814 1808. E-mail: phn{at}bio.aau.dk

Published ahead of print on 24 April 2009.

---

Applied and Environmental Microbiology, June 2009, p. 4101-4110, Vol. 75, No. 12
0099-2240/09/$08.00+0     doi:10.1128/AEM.02107-08
Copyright © 2009, American Society for Microbiology. All Rights Reserved.