Taxonomic Significance of Respiratory Quinones and Fumarate Respiration in Actinobacillus and Pasteurella

Abstract

The lipoquinones and associated respiratory functions of 34 cultures representing 17 bacterial species hitherto assigned to the genus Actinobacillus or Pasteurella were investigated. Strains representing recognized Actino bacillus or Pasteurella species regularly contained desmethylmenaquinones and were capable of anaerobic electron transport with fumarate as a terminal acceptor when grown in oxygen-limited cultures. On aeration, the majority of the strains produced ubiquinones in addition to desmethylmenaquinones, with inter-and intraspecific variations. The use of lipoquinone patterns and features indicating fumarate respiration, such as stimulation of oxygen-limited growth by fumarate, in the classification and identification of Actinobacillus, Pasteurella, and phenotypically similar organisms is discussed.In the 8th edition of Bergey's Manual, four species of the genus Pasteurella Trevisan and two species of the genus Actinobacillus Brumpt are recognized, and, furthermore, some species incertae sedis are listed (7, 10). Several species of Pasteurella and Actinobacillus described more recently are waiting for recognition or rejection. On the basis of phenotypical data, both circumscription of the two traditional genera and their classification below the generic level are at present difficult to assess. Moreover, Pasteurella and Actinobacillus are closely related at least to some members of the conventional genus Haemophilus (10). Thus, additional classifying features of the organisms in question are desired.After a preliminary study on the composition of the respiratory chain system of some Actinobacillus and Pasteurella strains (R. Zabel for 20 min before pouring) was used for maintenance and purity checks. Proteose peptone medium (14) with proteose peptone no. 3 (Difco) was used throughout for mass cultivation; the peptone lots used were known to contain less than lo-'' mol of both benzo-and naphthoquinones per g of dry weight (R. Hollander and W. Mannheim, unpublished data). Disodium fumarate (Fluka AG., Buchs, Switzerland; sterilized by filtration) was supplemented to a final concentration of 50 mM where indicated. "Aerobic" cells were grown by shaking 250-ml batches in Fernbach flasks (no. 20511, Schott & Gen., Mainz, Germany), using a rotary shaker (model G-25, New Brunswick Scientific Co., New Brunswick, N.J.), the shaking frequency depending on the sensitivity of the cultivated organism to aeration. "Oxygen-limited" cells were harvested from Fernbach flasks filled to the neck (about 2,000 ml of medium) and incubated statically. Incubation temperature was 37°C except for P. piscicida, which was grown at 25°C. Late-exponential-phase cells were sedimented at 12,000 x g, 0 to 4"C, and washed twice with 0.1 M tris(hydroxymethy1)aminomethane-hydrochloride buffer, pH 7.2.Determination of protein. Protein was determined, after sonic disintegration of the cells, by a modified biuret method (12).Determination of NADH oxidase and NADHfumarate reductase activities. Oxidation of reduced p-nicotinamade adenine dinu...

Classification of the Flavobacterium-Cytophaga Complex on the Basis of Respiratory Quinones and Fumarate Respiration

“…Since, as a rule, quinQne patterns define well-established groups of chemoorganotrophic bacteria (9,19), the taxonomic implications of this hding had to be considered. Therefore, the investigation was extended to a number of collection cultures representing several more-or-less recognized Flauobacterium or Cytophaga species.…”

Haemophilus ducreyi Isoprenoid Quinone Content and Structure Determination

“…Isoprenoid quinones of bacteria are lipophilic components of the cytoplasmic membrane (5, 8) that play important roles in the transfer of electrons in the respiratory chain and function in oxidative phosphorylation and active transport (5,7,8,20). The class of quinone and the length and degree of saturation of the isoprenoid side chain are useful in bacterial taxonomy (8,9,16,17,22). In general, strains that are about 70% or more related as determined by DNA-DNA hybridization contain the same quinone type and isoprene chain length, whereas a particular quinone structural type(s) is usually characteristic at the genus or family level (16,22).…”

“…The class of quinone and the length and degree of saturation of the isoprenoid side chain are useful in bacterial taxonomy (8,9,16,17,22). In general, strains that are about 70% or more related as determined by DNA-DNA hybridization contain the same quinone type and isoprene chain length, whereas a particular quinone structural type(s) is usually characteristic at the genus or family level (16,22).…”

Energy metabolism of Actinobacillus actinomycetemcomitans during anaerobic and microaerobic growth in low- and high-potassium continuous culture

“…One possible explanation for this small increase in the growth yield was an increase in substrate-level phosphorylation at the site of acetate kinase in the fructose fermentation (Ohta et al, 1996b). Alternatively, the occurrence of respiratory-chain phosphorylation was possible, since A. actinomycetemcomitans has a respiratory system with oxygen as the terminal electron acceptor (Mannheim et al, 1978).…”