title: Growth of halotolerant food spoiling yeast Debaryomyces nepalensis NCYC 3413 under the influence of pH and salt.
abstract: Debaryomyces nepalensis, a halotolerant food-spoiling yeast could grow in complex (YEPD) medium at different pHs ranging between 3.0 and 11.0 in the absence of salt and at pH 3.0-9.0 in the presence of different concentrations of NaCl and KCl. The specific growth rate of D. nepalensis was not affected by the initial pH of the medium in the absence of salts, whereas it was affected in the presence of salts. At 2 M NaCl and KCl, the organism exhibited a synergistic effect on pH and salt stress, which was unique in the Debaryomyces species. Irrespective of the initial pH and salt, the intracellular pH of D. nepalensis was approximately 7.0. Significant organic acid was produced at neutral and alkaline pH and organic acid production increased with the increase in pH and salt. Very specific organic acids are produced in the presence of NaCl and KCl. Our observation would contribute to a better understanding of the physiological phenomenon of halotolerance in D. nepalensis.
authors.affiliation: Applied and Industrial Microbiology Laboratory, Department of Biotechnology, Indian Institute of Technology-Madras, Chennai 600 036, India.
authors.forename: Sawan
authors.initials: S
authors.lastname: Kumar
authors.forename: Pradeep
authors.initials: P
authors.lastname: Lal
authors.forename: Sathyanarayana N
authors.initials: SN
authors.lastname: Gummadi
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology*; D002264:Carboxylic Acids / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D003600:Cytosol / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D011189:Potassium Chloride / Q000494:pharmacology*; D004718:Saccharomycetales / Q000187:drug effects* / Q000254:growth & development*; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D002264:Carboxylic Acids; D003470:Culture Media; D012965:Sodium Chloride; D011189:Potassium Chloride