Seed culture and its effect on the growth and lactic acid production of Lactobacillus helveticus.
Effects of seed culture medium on the subsequent culture of L. helveticus growing on whey supplemented with yeast extract and peptones have been examined. Cells were inoculated when the maximum cellular activity was achieved, i.e. the maximum for the target function, the product of the specific growth rate with the undissociated lactic acid concentration. This function decreased when the nitrogen supplementation of the preculture medium was lowered, resulting only in an increase of the lag phase length of the culture, corresponding to a cellular adaptation to the new medium. On the contrary, when cells were not in the same physiological state, growth and production parameters were affected, maximum rates, as well as maximum biomass concentration. This occurred in case of the comparison of inocula carried out under pH control or not, or when various preculture lengths were tested.
Amrane
Abdeltif
A
Laboratoire des Procédés de Séparation (UPRES EA 3191, UC I.N.R.A.), Université de Rennes 1, Băt. 10 A, 263 avenue du Général Leclerc, CS 74205, 35042 Rennes Cedex, France. abdeltif.amrane@univ-rennes1.fr
D019149:Bioreactors / Q000382:microbiology; D002455:Cell Division; D003470:Culture Media; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000096:biosynthesis*; D007778:Lactobacillus / Q000145:classification / Q000254:growth & development* / Q000378:metabolism*; D008894:Milk Proteins / Q000378:metabolism; D000067816:Whey Proteins
D003470:Culture Media; D008894:Milk Proteins; D000067816:Whey Proteins; D019344:Lactic Acid