Role of pfkA and General Carbohydrate Catabolism in Seed Colonization by Enterobacter cloacae

摘要: Enterobacter cloacae A-11 is a transposon mutant of strain 501R3 that was deficient in cucumber spermosphere colonization and the utilization certain carbohydrates (D. P. Roberts, C. J. Sheets, S. Hartung, Can. Microbiol. 38:1128–1134, 1992). In vitro growth reduced or on most supported but unaffected fructose, glycerol, all amino acids organic tested. Colonization by significantly (P ≤ 0.05) for radish seeds compared to 501R3, pea, soybean, sunflower, sweet corn not reduced. Pea released several orders magnitude more total than approximately 4,000-fold fructose. Fructose only carbohydrate detected seed exudates which wild-type levels A-11. Soybean, also greater amounts fructose seeds. The exogenous addition at quantities similar quantity from pea over 96 h increased populations comparable those sterile sand. Molecular characterization indicated mini-Tn5 kanamycin inserted region genome with significant homology pfkA, encodes phosphofructo kinase. A comparison Escherichia coli DF456, known pfkA mutant, nutritional loss phenotypes were identical. Furthermore, homolog cloned E. complemented both DF456 restored near levels. These genetic biochemical restoration experiments provide strong evidence carbon sources found ability microbes use these compounds play important roles spermosphere.