Effects of cellulose on growth, enzyme production, and ultrastructure of a Cellulomonas species

Abstract

Cellulomonas sp. (NRCC 2406) was grown on complex medium (peptone-tryptone-yeast extract) alone, or with the addition of different celluloses (solka floc, avicel, CF 11 cellulose or Whatman No. 1 filter paper) and/or glucose. Cultures growing on the complex medium without cellulose produced low levels of endo- and exo-cellulases and very little β-glucosidase. Adding cellulose stimulated growth, as measured by cellular protein or by viable counts, and also stimulated production of cellulases. Adding glucose in the prescene of cellulose inhibited growth and cellulose breakdown. Glucose also inhibited attachment of growing cells to cellulose fibres. Electron microscope studies showed that Cellulomonas sp. adhered to the cellulose fibers. In the presence of cellulose in the media, the cells developed a thicker outer layer which probably helps in the adhesion process.