Microaerophilic property of Actinobacillus actinom

Authors: Ohta Hiroyuki Moriki Daisuke Miyagi Atsushi Watanabe Tatsuo Kato Keijiro Fukui Kazuhiro

Publish Date: 1996/05/01

Volume: 138, Issue: 2-3, Pages: 191-196

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Abstract

Hiroyuki Ohta Daisuke Moriki Atsushi Miyagi Tatsuo Watanabe Keijiro Kato Kazuhiro Fukui Microaerophilic property of Actinobacillus actinomycetemcomitans in fructoselimited chemostat cultures FEMS Microbiology Letters Volume 138 Issue 23 May 1996 Pages 191–196 https//doiorg/101111/j157469681996tb08155xThe effect of oxygen on the growth metabolism and leukotoxin production of Actinobacillus actinomycetemcomitans 301b was examined using a chemostat equipped with a redox potential control system Steady states were obtained with fructoselimited cultures grown at a dilution rate of 01 h−1 under strictly anaerobic Eh=−460 mV and microaerobic conditions Eh≤ 150 mV but not under highly aerated conditions Eh≥ 100 mV The optimum growth was recorded at Eh=−300 to − 200 mV and the recorded Yfructose value was about 13 times the Yfructose of anaerobic cultures Although the organism contains a respiratory chain the increased Yfructose under the microaerobic conditions might result from the increased substratelevel phosphorylation at the site of acetate kinase but not from electron transport phosphorylation After passing threshold aeration Eh=−100 mV the culture yielded a variant with transparent colony morphology Under anaerobic conditions the Yfructose of the variant was about 16 times that of the original opaque colonyforming cells The optimum growth of the variant was also recorded at Eh=− 300 to − 200 mV In both types of cells the production of leukotoxin reached a maximum at Eh=−350 to − 200 mV These findings suggested the microaerophilic nature of A actinomycetemcomitans

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