The growth response of Listena monocytogenes strains A4413 and 9037-7 to carbohydrates was determined in a defined medium. Neither pyruvate, acetate, citrate, isocitrate, a-ketoglutarate, succinate, fumarate, nor malate supported growth. Furthermore, inclusion of any of these carbohydrates in the growth medium with glucose did not increase the growth of Listeria over that observed on glucose alone. Resting cell suspensions of strain A4413 oxidized pyruvate but not acetate, citrate, isocitrate, a-ketoglutarate, succinate, fumarate, or malate. Cell-free extracts of strain A4413 contained active citrate synthase, aconitate hydratase, isocitrate dehydrogenase, malate dehydrogenase, fumarate hydratase, fumarate reductase, pyruvate dehydrogenase system, and oxidases for reduced nicotinamide adenine dinucleotide and reduced nicotinamide adenine dinucleotide phosphate. The a-ketoglutarate oxidation system, succinate dehydrogenase, isocitrate lyase, and malate synthase were not detected. Cytochromes were not detected. The data suggest that strain A4413, under these conditions, utilizes a split noncyclic citrate pathway which has an oxidative portion (citrate synthase, aconitate hydratase, and isocitrate dehydrogenase) and a reductive portion (malate dehydrogenase, fumarate hydratase, and fumarate reductase). This pathway is probably important in biosynthesis but not for a net gain in energy. I This paper is taken from a dissertation presented to the Department of Microbiology and the Graduate Division of the University of Oregon Medical School by Terrence L. Trivett in partial fulfillment of the requirements for the Ph.D. degree.

Cyanide-poisoned Neisseria meningitidis SD1C cells rapidly took up 'Fe from iron-citrate complexes during the first 2 min, after which no further iron was accumulated. ['4C]citrate was not taken up concomitantly with 'Fe by these cells.The 'Fe taken up by the poisoned cells was found in the membrane fraction after cells were broken; 70% of the radioactivity was distributed in the outer membrane, and 30% was in the inner membrane. Isolated outer membranes from iron-starved cells were as capable of iron uptake from citrate as intact cells were. As with whole cells, ['4C]citrate was not taken up by isolated outer membranes. A polyacrylamide gel electrophoresis analysis of the proteins from citrate-dialyzed outer membranes after the uptake of 'Fe revealed that the radioactivity was associated with a major band of 36,500 molecular weight.Other recent evidence has shown that meningococci can use human transferrin-bound iron as t Permanent address: Department of Biology, Pacific Union College, Angwin CA 94508. 50 ng of ferrous ammonium sulfate per ml (final concentration) to a final optical density at 600 nm of 0.3 (model 250 spectrophotometer; Gilford Instrument Laboratories, Ontario, Canada). A 75-ml volume of this suspension was the inoculum for 1,425 ml of NDM.The final culture medium contained less than 10 ng of Fe per ml as contaminating iron before inoculation.Cultures in this iron-limited medium (Fig. 1) were incubated at 37°C, in 5% CO2 in air until division in 547 on August 3, 2020 by guest http://iai.asm.org/ Downloaded from

In ruminants, such as cattle, sheep, and goats, common forms of listeriosis are abortion, stillbirth, or postnatal death of the young infected animal (M. L.