Are gram-positive bacteria capable of electron transfer across their cell wall without an externally available electron shuttle?


Corresponding author: H. L. Ehrlich. Tel.: (518) 276-8428; fax: (518) 276-2344; e-mail:


The extensive contributions by Terry Beveridge to our understanding of the differences in cell wall organization with respect to structure, chemistry and compartmentalization between gram-positive and gram-negative bacteria are summarized. These contributions greatly aided in conceptualization of recent discoveries concerning electron export and import across cell walls of some gram-negative bacteria. Although electron export and import across the cell wall by any gram-positive has not been documented so far, Beveridge's observations and concepts concerning cell walls of gram-positive bacteria suggest potential mechanisms by which such electron transfer may occur.