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The influence of 2,4‐dichlorophenoxyacetic acid on lactic acid bacteria
Author(s) -
Libudzisz Z.,
Kirkwood R. C.
Publication year - 1983
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740341109
Subject(s) - lactose , lactic acid , lactobacillus casei , bacteria , population , strain (injury) , metabolism , food science , biology , lactobacillaceae , bacterial growth , chemistry , microbiology and biotechnology , biochemistry , fermentation , genetics , demography , anatomy , sociology
The effect of 2,4‐dichlorophenoxyacetic acid (2,4‐D) (4 × 10 −5 M‐4 × 10 −3 M) on the growth and physiological activity of Streptococcus lactis subsp. diacetylactis and Lactobacillus casei has been investigated when cultivated in milk and lactose‐peptone media. The concentrations of 2,4‐D applied in milk did not cause complete growth inhibition of any of the strains. The degree of inhibition was dependent upon the bacterium species and the herbicide dose. Growth of the tolerant strain— L. casei W‐10 —was reduced by about 40% (in the presence of 4 × 10 −3 M 2,4‐D), whereas the the level of lactic acid production remained almost unchanged. Under the same conditions, growth of the sensitive strain S. lactis subsp. diacetylactis 239 was reduced by almost 25 times and lactic acid production inhibited by about 40% in comparison with the controls. Cultivation of S. lactis subsp. diacetylactis 239 in lactose‐peptone medium with 2 × 10 −3 M 2,4‐D was characterised by a lengthened lag‐phase, lengthened generation time (3 times) and an increased rate of herbicide metabolism. In addition, selective or mutative action of 2,4‐D has been shown. Herbicide treatment inhibited the cells of c.f.u. producing the least acid and enhanced the contribution of the active ones. Cells of c.f.u. with activities not found in the control population have also been revealed. Both species of bacteria were capable of metabolism of 2,4‐D to 2,4‐dichlorophenol.