Int. J. Mol. Sci. 2006, 7, 1-11 International Journal of Molecular Sciences ISSN 1422-0067 © 2006 by MDPI www.mdpi.org/ijms/ Location, formation and biosynthetic regulation of cellulases in the gliding bacteria Cytophaga hutchinsonii Clifford Louime 1,* , Michael Abazinge 1 and Elijah Johnson 1 1 Florida A&M University, Environmental Sciences Institute, FSH Science Research Center, 1520 South Bronough Street, Tallahassee, FL 32307, USA. * Current address of author to whom correspondence should be addressed: University of Maryland School of Medicine, Department of Medical Research and Technology, 100 Penn Street, Baltimore, MD 21201, USA. Email:
[email protected], Phone: 410-706-7664, Fax: 410-706-0073. Received: 27 December 2006 / Accepted: 30 January 2006 / Published: 31 January 2006 Abstract: An analysis of the recently published genome sequence of Cytophaga hutchinsonii revealed an unusual collection of genes for an organism that can attack crystalline cellulose. Consequently, questions were being raised by cellulase scientists, as to what mechanism this organism uses to degrade its insoluble substrates. Cellulose, being a highly polymeric compound and insoluble in water, cannot enter the cell walls of microorganisms. Cellulose-degrading enzymes have therefore to be located on the surface of the cell wall or released extracellularly. The location of most cellulase enzymes has been studied. However, basic information on C. hutchinsonii cellulases is almost non-existent. In the present study, the location, formation and biosynthetic regulation of cellulases in C. hutchinsonii were demonstrated on different substrates. Various fractions isolated from C. hutchinsonii after cell rupture were assayed for carboxymethyl-cellulase activity (CMC). The cellulases were found to be predominantly cell-free during active growth on solka-flok, although 30% of activity was recorded on cell-bound enzymes.