Open AccessEffects of oxygen on the growth and metabolism of Actinomyces viscosus
Author(s) -
Jong M.H.,
Hoeven J.S.,
Kieboom C.W.A.,
Camp P.J.M.
Publication year - 1988
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.1574-6968.1988.tb02646.x
Subject(s) - chemostat , anaerobic exercise , chemistry , fermentation , oxygen , metabolism , electron transport chain , electron acceptor , cytochrome , biochemistry , cellular respiration , bacteria , microbiology and biotechnology , biology , enzyme , organic chemistry , mitochondrion , physiology , genetics
Actinomyces viscosus is a predominant microorganism in dental plaque. It is, just as the oral Streptococcus spp., a saccharolytic and aero‐tolerant organism. We have investigated the effects of oxygen on the growth and metabolism of A. viscosus . To this end A. viscosus Ut 2 was grown in a glucose limited chemostat culture on a chemically defined medium ( D = 0.2 h −1 ) with exposure to variable amounts of oxygen. The Y glucose increased from 62.5 g · mol −1 under anaerobic conditions to 149 g · mol −1 under aerobic conditions, while, concomitantly, the carbon recovery from acidic fermentation products decreased from 75% to 7%. Addition of [ 14 C]glucose to the chemostat showed that the glucose, which was not converted to acidic fermentation products, was instead converted to carbon dioxide or used for the production of biomass. Under aerobic and anaerobic conditions identical cytochrome spectra, containing only two cytochrome b ‐type absorption bands, were found. It was concluded that electron transport phosphorylation probably occurs both under aerobic and anaerobic conditions. Anaerobically, fumarate served as the electron acceptor, while the high growth yields observed under aerobic conditions are likely to be explained by citric acid cycle activity coupled to electron transport phosphorylation.