Water relations of Erwinia chrysanthemi: intracellular and extracellular pectate lyase production

• Published in: Journal of general microbiology Vol. 129; no. 10; pp. 3019 - 3025
• Main Authors: Mildenhall, J.P, Prior, B.A
• Format: Journal Article
• Language: English
• Published: London Soc General Microbiol 1983; New York, NY Cambridge University Press
• Subjects: bacterial diseases of plants; Bacterial plant pathogens; Biological and medical sciences; Erwinia chrysanthemi; Fundamental and applied biological sciences. Psychology; Phytopathology. Animal pests. Plant and forest protection; plant health; plant pathogenic bacteria; Water; Sorbitol; Laboratory study; Pectate lyase; Growth; Lithium Chlorides; Phytopathogen; Sodium Sulfides; Solutes; Water activity; Enzymatic activity; Erwinia chrysanthemi; Production; Bacteria; Potassium Chlorides; Sodium Chlorides
• ISSN: 0022-1287; 1350-0872; 1465-2080
• DOI: 10.1099/00221287-129-10-3019

1 Faculty of Agriculture, University of Fort Hare, Alice 5700, Ciskei, South Africa 2 Department of Microbiology, University of the Orange Free State, Bloemfontein 9300, South Africa ABSTRACT Summary: When Erwinia chrysanthemi was grown in a sodium polypectate/yeast extract/salts medium adjusted with sorbitol to water activity ( a w ) values of 0.990 and 0.980, extracellular pectate lyase (PL) production was repressed, whereas intracellular PL levels were not affected. Inorganic solutes (NaCl. LiCl, KCl, Na 2 SO 4 and a NaCl/KCl/Na 2 SO 4 mixture) at 0.990 aw strongly stimulated the intracellular levels of PL (6- to 17-fold greater than the control), whereas extracellular levels were only slightly increased. Intra- and extracellular PL levels were not affected by LiCl, NaCl and KCl at 0.995 a w . A NaCl/sorbitol mixture (0.990 a w ) completely inhibited extracellular but not intracellular PL production. Lowering of the aw of cultures during mid-exponential growth phase with NaCl (0.990 a w ) resulted within 30 min in a 70-fold increase in intracellular PL activity. When sorbitol was used in similar experiments, extracellular PL production was inhibited to a greater extent than intracellular levels.