Taxonomic Diversity of the D-Glucose Oxidation Pathway in the Enterobacteriaceae

Abstract

Tests allowing the screening of large numbers of enterobacterial strains for the presence of the glucose oxidation pathway (glucose, gluconate, and 2-ketogluconate dehydrogenases) were devised or adapted. A total of 506 strains representing 111 taxa (named species or subspecies and unnamed genomic groups) were studied. The members of the genera Budvicia, Edwardsiella, Leminorella, Providencia, and Xenorhabdus and the species Citrobacter freundii, Erwinia carnegeana, Erwinia carotovora, Erwinia chrysanthemi, Erwinia nigrifluens, Erwinia salicis, Moellerella wisconsensis, Proteus penneri, Proteus vulgaris, Yersinia intermedia, Yersinia pestis, Yersinia pseudotuberculosis, and Yersinia ruckeri were negative in all tests. Five species, Erwinia cypripedii, Ewingella americana, Rahnella aquatilis, Serratia marcescens (at 20°), and Tatumella ptyseos produced 2,5-diketogluconate from glucose without a requirement for pyrroloquinoline quinone (PQQ). When PQQ was provided (required for glucose oxidation), Serratia grimesii and Serratia liquefaciens produced 2,5-diketogluconate from glucose at 20°. Escherichia blattae had gluconate- and 2-ketogluconate dehydrogenases without glucose dehydrogenase. The members of the genera Hafnia, Obesumbacterium, and Pragia had only gluconate dehydrogenase. Other species had glucose dehydrogenase (with or without a requirement for PQQ) with or without gluconate dehydrogenase. Classification and identification may take advantage of tests exploring the glucose oxidation pathway.