title: Hydrogen sulfide production from cysteine and homocysteine by periodontal and oral bacteria.
abstract: BACKGROUND
  Hydrogen sulfide is one of the predominant volatile sulfur compounds (VSCs) produced by oral bacteria. This study developed and evaluated a system for detecting hydrogen sulfide production by oral bacteria.
  
  
  METHODS
  L-methionine-alpha-deamino-gamma-mercaptomethane-lyase (METase) and beta carbon-sulfur (beta C-S) lyase were used to degrade homocysteine and cysteine, respectively, to produce hydrogen sulfide. Enzymatic reactions resulting in hydrogen sulfide production were assayed by reaction with bismuth trichloride, which forms a black precipitate when mixed with hydrogen sulfide. The enzymatic activities of various oral bacteria that result in hydrogen sulfide production and the capacity of bacteria from periodontal sites to form hydrogen sulfide in reaction mixtures containing L-cysteine or DL-homocysteine were assayed.
  
  
  RESULTS
  With L-cysteine as the substrate, Streptococcus anginosus FW73 produced the most hydrogen sulfide, whereas Porphyromonas gingivalis American Type Culture Collection (ATCC) 33277 and W83 and Fusobacterium nucleatum ATCC 10953 produced approximately 35% of the amount produced by the P. gingivalis strains. Finally, the hydrogen sulfide found in subgingival plaque was analyzed. Using bismuth trichloride, the hydrogen sulfide produced by oral bacteria was visually detectable as a black precipitate.
  
  
  CONCLUSIONS
  Hydrogen sulfide production by oral bacteria was easily analyzed using bismuth trichloride. However, further innovation is required for practical use.
authors.affiliation: Division of Community Oral Health Science, Department of Health Promotion, Kyushu Dental College, Kitakyushu, Japan. akihiro@kyu-dent.ac.jp
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yoshida
authors.forename: Mamiko
authors.initials: M
authors.lastname: Yoshimura
authors.forename: Naoya
authors.initials: N
authors.lastname: Ohara
authors.forename: Shigeru
authors.initials: S
authors.lastname: Yoshimura
authors.forename: Shiori
authors.initials: S
authors.lastname: Nagashima
authors.forename: Tadamichi
authors.initials: T
authors.lastname: Takehara
authors.forename: Koji
authors.initials: K
authors.lastname: Nakayama
mesh_terms: D000328:Adult; D000368:Aged; D001419:Bacteria / Q000378:metabolism*; D001439:Bacteroides / Q000378:metabolism; D001729:Bismuth; D013437:Carbon-Sulfur Lyases / Q000378:metabolism; D002712:Chlorides; D003545:Cysteine / Q000378:metabolism*; D003773:Dental Plaque / Q000382:microbiology; D016983:Enterococcus / Q000378:metabolism; D005260:Female; D016967:Fusobacterium nucleatum / Q000378:metabolism; D006710:Homocysteine / Q000378:metabolism*; D006801:Humans; D006862:Hydrogen Sulfide / Q000378:metabolism*; D007202:Indicators and Reagents; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000382:microbiology*; D010510:Periodontal Diseases / Q000382:microbiology*; D010514:Periodontal Pocket / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000378:metabolism; D018713:Prevotella intermedia / Q000378:metabolism; D045242:Prevotella nigrescens / Q000378:metabolism; D013291:Streptococcus / Q000378:metabolism; D034366:Streptococcus anginosus / Q000378:metabolism
chemical_list: D002712:Chlorides; D007202:Indicators and Reagents; D006710:Homocysteine; C534543:bismuth trichloride; D013437:Carbon-Sulfur Lyases; C021558:L-methionine gamma-lyase; D003545:Cysteine; D001729:Bismuth; D006862:Hydrogen Sulfide