Microbial Ecology

, Volume 55, Issue 2, pp 212–219

B. thuringiensis is a Poor Colonist of Leaf Surfaces

Authors

  • Pau Maduell
    • Biotechnology and Biological Control Unit, Corporación para Investigaciones Biológicas
    • Microbiology Unit, Department of Genetics and MicrobiologyUniversitat Autònoma de Barcelona
  • Gemma Armengol
    • Biotechnology and Biological Control Unit, Corporación para Investigaciones Biológicas
    • Department of Animal Biology, Vegetal Biology and EcologyUniversitat Autònoma de Barcelona
  • Montserrat Llagostera
    • Microbiology Unit, Department of Genetics and MicrobiologyUniversitat Autònoma de Barcelona
  • Sergio Orduz
    • Biotechnology and Biological Control Unit, Corporación para Investigaciones Biológicas
    • Universidad Nacional de Colombia sede Medellín
    • Department of Plant and Microbial BiologyUniversity of California
Original Article

DOI: 10.1007/s00248-007-9268-4

Cite this article as:
Maduell, P., Armengol, G., Llagostera, M. et al. Microb Ecol (2008) 55: 212. doi:10.1007/s00248-007-9268-4

Abstract

The ability of several Bacillus thuringiensis strains to colonize plant surfaces was assessed and compared with that of more common epiphytic bacteria. While all B. thuringiensis strains multiplied to some extent after inoculation on bean plants, their maximum epiphytic population sizes of 106 cfu/g of leaf were always much less than that achieved by other resident epiphytic bacteria or an epiphytically fit Pseudomonas fluorescens strain, which attained population sizes of about 107 cfu/g of leaf. However B. thuringiensis strains exhibited much less decline in culturable populations upon imposition of desiccation stress than did other resident bacteria or an inoculated P. fluorescens strain, and most cells were in a spore form soon after inoculation onto plants. B. thuringiensis strains produced commercially for insect control were not less epiphytically fit than strains recently isolated from leaf surfaces. The growth of B. thuringiensis was not affected by the presence of Pseudomonas syringae when co-inoculated, and vice versa. B. thuringiensis strains harboring a green fluorescent protein marker gene did not form large cell aggregates, were not associated with other epiphytic bacteria, and were not found associated with leaf structures, such as stomata, trichomes, or veins when directly observed on bean leaves by epifluorescent microscopy. Thus, B. thuringiensis appears unable to grow extensively on leaves and its common isolation from plants may reflect immigration from more abundant reservoirs elsewhere.

Copyright information

© Springer Science+Business Media, LLC 2007