title: Effect of culture conditions on lactic acid production of Tetragenococcus species.
abstract: OBJECTIVE
  To investigate the effects of the salt concentration, incubation temperature and initial pH of the medium on the fermentative ability of the halophilic lactic acid bacteria, Tetragenococcus muriaticus and T. halophilus.
  
  
  RESULTS
  The growth, lactic acid production and pH reduction ability of five strains of T. muriaticus and T. halophilus in MRS broth medium under various culture conditions such as salt concentration (3, 7, 15 and 23% NaCl), temperature (20, 30 and 40 degrees C), and initial medium pH (5.8, 6.5 and 7.5) were investigated. Those of T. halophilus were seriously affected by a high salinity (23% NaCl); in contrast, those of T. muriaticus were affected by a low initial pH (5.8).
  
  
  CONCLUSIONS
  The results indicate that high saline concentrations and low pH values have significant impact on the growth, lactic acid production and pH reduction ability of T. halophilus and T. muriaticus, respectively.
  
  
  CONCLUSIONS
  This study appears to be important in biopreservation during the manufacture of fermented food products. Both T. muriaticus and T. halophilus may support each other in reducing pH in hypersaline or low pH environment. To our knowledge, this is the first report on the fermentation ability of T. muriaticus.
authors.affiliation: Graduate School of Marine Science and Technology, Tokyo University of Marine Science and Technology, Minato-ku, Tokyo, Japan. takeshik@s.kaiyodai.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: M
authors.initials: M
authors.lastname: Kajiwara
authors.forename: M
authors.initials: M
authors.lastname: Wahyuni
authors.forename: N
authors.initials: N
authors.lastname: Hamada-Sato
authors.forename: C
authors.initials: C
authors.lastname: Imada
authors.forename: E
authors.initials: E
authors.lastname: Watanabe
mesh_terms: D004305:Dose-Response Relationship, Drug; D005285:Fermentation / Q000187:drug effects; D005516:Food Microbiology; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000379:methods; D019344:Lactic Acid / Q000096:biosynthesis*; D007778:Lactobacillus / Q000145:classification / Q000187:drug effects / Q000378:metabolism*; D012965:Sodium Chloride / Q000008:administration & dosage; D013696:Temperature
chemical_list: D019344:Lactic Acid; D012965:Sodium Chloride