VIEW ARTICLE

Degradation of Xylan by Bacterial Plant Pathogens. A. L. Maino, Assistant Research Plant Pathologist, Department of Plant Pathology and Department of Bacteriology and Immunology, University of California, Berkeley 94720; M. N. Schroth(2), and N. J. Palleroni(3). (2)(3)Professor, and Research Bacteriologist, respectively, Department of Plant Pathology and Department of Bacteriology and Immunology, University of California, Berkeley 94720. Phytopathology 64:881-885. Accepted for publication 24 January 1974. DOI: 10.1094/Phyto-64-881.

Sixty-three plant pathogenic bacteria (41 species) and seven saprophytes (three species) were tested for their capacity to degrade xylan with simultaneous release of reducing sugars into the culture medium. Of these only Achromobacter sp., Pseudomonas acidovorans, P. apii, P. flectans, and Erwinia quercina were positive. With Achromobacter strains, significant amounts of reducing sugars accumulated during growth on 1.0% xylan. Xylose was the principal monosaccharide remaining in culture filtrates of Achromobacter strains. Other degradation products included arabionose, galactose, mannose, glucose, di- and trisaccharides. Xylanase activities of 1.3 - 2.8 µmoles reducing sugar/min/mg protein were detected in culture filtrates of Achromobacter. Xylanase was not detected, either as an extracellular or intracellular enzyme, in P. phaseolicola when corn cob xylan was used as a growth substrate.