Naomi Sato

Degradation of arginine and other amino acids by butyrate-producing asaccharolytic anaerobic Gram-positive rods in periodontal pockets

The use of 20 amino acids by butyrate-producing asaccharolytic anaerobic Gram-positive rods (AAGPRs) in periodontal pockets, i.e. Eubacterium minutum, Filifactor alocis, E. infirmum, E. sulci and E. saphenum, was studied. E. minutum used only arginine and lysine, and produced substantial amounts of butyrate and ammonia as the main metabolic products from arginine, and acetate, butyrate and ammonia from lysine. Fi. alocis used arginine alone and produced butyrate and ammonia. E. infirmum, E. sulci and E. saphenum used lysine alone and produced acetate, butyrate and ammonia. The growth of these bacterial species was supported and enhanced by arginine and/or lysine enriched to culture media, but not by the other amino acids. Arginine deiminase, ornithine carbamoyltransferase and carbamate kinase activity were detected in the cell-free extract of E. minutum, suggesting that arginine was metabolised to citrulline initially, and subsequently to ornithine and carbamoyl phosphate. Ornithine and carbamoyl phosphate were further converted to butyrate, and carbon dioxide and ammonia, respectively. Enzymatic activity of arginine deiminase and ornithine carbamoyltransferase was not detected in Fi. alocis, indicating that Fi. alocis converted arginine to ornithine directly, not via citrulline, and further to butyrate.

Chemical structure of the polysaccharide antigen of Eubacterium saburreum, strain O2

The polysaccharide antigen produced by Eubacterium saburreum, strain O2, is composed of (1 leads to 6)-linked beta-D-glycero-D-galacto-heptopyranosyl residues, all of which are substituted with 6-deoxy-alpha-D-altro-heptofuranosyl groups at O-3.

Properties of the human salivary aggregating factor for Leptotrichia buccalis cells

Abstract Leptotrichia buccalis cell-aggregating and blood-group substance appeared in the void-volume in gel filtration of human whole saliva on Sepharose 2B. The void-volume material remained in the sample gel in the disc gel electrophoresis at pH 9.5 and gave a single sedimentation peak in ultracentrifugation. Three preparations with different blood group substance activities, A, H and Le a , contained 18.2–22.2 per cent protein and 77.8–81.8 per cent carbohydrate. The carbohydrate was composed of glucosamine, galactosamine, fucose and galactose. Amino acid compositions of the three preparations were very similar, with the main acids being threonine, serine and proline followed by alanine and glycine. Total moles of the hydroxy-amino acids were about equal to the moles of galactosamine residue, except in the preparation from secretory saliva with blood-group A specificity. The findings suggest that the cell-aggregating factor is a high molecular-weight glycoprotein with blood-group activity. Isoelectric-focusing analysis revealed that the cell-aggregating factor was heterogeneous with respect to electrophoretic property. The cell-aggregating components were always accompanied by varying levels of blood-group activity.

The structure of the antigenic polysaccharide produced by Eubactrium saburreum T15.

The antigenic polysaccharide was obtained from the cell wall of Eubacterium saburreum strain T15 by trypsin digestion followed by gel permeation and ion-exchange chromatography. Its structure was determined using acid hydrolysis, methylation analysis, and 1D and 2D NMR spectroscopy. It contained L-threo-pent-2-ulose (Xul), D-fucose (Fuc), and D-glycero-D-galacto-heptose (Hep) in 2:3:3 ratio. Methylation analysis indicated an octasaccharide repeating-unit containing five branches. The 1H and 13C signals in NMR spectra of the sugar residues were assigned by COSY, HOHAHA, and HMQC 2D experiments, and the sequence of sugar residues in the repeating unit was determined by NOESY and HMBC experiments. The polysaccharide also contains two O-acetyl groups in the repeating unit, located on the Hep residue. The repeating structure can be written as: [see text for equation]. This is a novel structure in bacterial cell-wall polysaccharides from Gram-positive bacteria.

Campylobacter rectus and Campylobacter gracilis Isolated from Human Periodontal Pockets

Abstract We previously isolated 40 predominant strains of bacteria, the characteristics of which resembled Wolinella (presently Campylobacter ), among 422 isolates from seven human periodontal pockets; however, at that time, exact identification was not possible by conventional microbiological and biochemical tests because the criteria were ambiguous. Therefore, in the present study we aimed to clarify the classifications of the 17 representative strains by polymerase chain reaction (PCR) using a species-specific primer, 16S rDNA sequence similarity, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and Western immunoblotting. We also aimed to describe each strains biochemical characteristics in detail. All of the 17 isolates studied were asaccharolytic, positive in nitrate reduction and arylsulfatase activity, negative in catalase and urease, and produced succinate as an end product of formate and fumarate for growth. Of the 17, 13 strains were identified as C. rectus , and 4 were oxidase negative strains ( C. gracilis ). Three of the C. gracilis strains were cocobacilli, which were morphologically different from the previously established strains. Evidence suggests that Campylobacter isolates from periodontal pockets in our previous work may be primarily C. rectus and secondarily C. gracilis .