Open AccessMajor differences between glutamate‐fermenting species isolated from chemostat enrichments at different dilution rates
Author(s) -
Nanninga Henk J.,
Drent Wim J.,
Gottschal Jan C.
Publication year - 1986
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1986.tb01744.x
Subject(s) - chemostat , fermentation , dilution , ammonium , propionate , bacteria , carbon dioxide , strain (injury) , chemistry , biology , glutamate receptor , food science , microbiology and biotechnology , biochemistry , organic chemistry , genetics , physics , receptor , anatomy , thermodynamics
From chemostat enrichments conducted at dilution rates of 0.025, 0.12 and 0.25 h −1 glutamate‐ and aspartate‐fermenting bacteria were isolated. The dominant aspartate‐fermenting strains in all these enrichments belonged to the genus Campylobacter , whereas 3 dissimilar types of glutamate‐fermenting bacteria predominated at the different dilution rates. One of these strains was identified as Clostridium cochlearium . The remaining two were designated as strain DKglu16 (glutamate → acetate + propionate + ammonium + carbon dioxide) and DKglu21 (glutamate → acetate + formate + ammonium + carbon dioxide). Grown in continuous culture under glutamate limitation, strain DKglu16 (μ max = 0.13 h −1 ; K s = 1.9 μM) outcompeted C. cochlearium (μ max = 0.36 h −1 ; K s = 7 μM) at low dilution rates, but was outgrown at higher rates of dilution (0.044 h −1 ). In glutamate‐limited continuous culture the competitiveness of strain DKglu16 increased considerably when lactate was added to the feed in addition to glutamate.