Factors Related to the Oxygen Tolerance of Anaerobic Bacteria

Abstract

The effect of atmospheric oxygen on the viability of 13 strains of anaerobic bacteria, two strains of facultative bacteria, and one aerobic organism was examined. There were great variations in oxygen tolerance among the bacteria. All facultative bacteria survived more than 72 h of exposure to atmospheric oxygen. The survival time for anaerobes ranged from less than 45 min for Peptostreptococcus anaerobius to more than 72 h for two Clostridium perfringens strains. An effort was made to relate the degree of oxygen tolerance to the activities of superoxide dismutase, catalase, and peroxidases in cell-free extracts of the bacteria. All facultative bacteria and a number of anaerobic bacteria possessed superoxide dismutase. There was a correlation between superoxide dismutase activity and oxygen tolerance, but there were notable exceptions. Polyacrylamide gel electropherograms stained for superoxide dismutase indicated that many of the anaerobic bacteria contained at least two electrophoretically distinct enzymes with superoxide dismutase activity. All facultative bacteria contained peroxidase, whereas none of the anaerobic bacteria possessed measurable amounts of this enzyme. Catalase activity was variable among the bacteria and showed no relationship to oxygen tolerance. The ability of the bacteria to reduce oxygen was also examined and related to enzyme content and oxygen tolerance. In general, organisms that survived for relatively long periods of time in the presence of oxygen but demonstrated little superoxide dismutase activity reduced little oxygen. The effects of medium composition and conditions of growth were examined for their influence on the level of the three enzymes. Bacteria grown on the surface of an enriched blood agar medium generally had more enzyme activity than bacteria grown in a liquid medium. The data indicate that superoxide dismutase activity and oxygen reduction rates are important determinants related to the tolerance of anaerobic bacteria to oxygen.

Microbial Mineralization of Dichloroethene and Vinyl Chloride under Hypoxic Conditions

“…The frequent observation of detection level of (DO concentrations between 0.05 and 0.1 mg/L) DO concentrations suggests a flux of DO into the plume (Figure 2) , although the ongoing Fe(III)-reduction within the chloroethene plume between the USGS 4 and USGS 8 transects demonstrates that the supply of O 2 is not sufficient to prevent the onset and apparent predominance of anaerobic redox conditions Bradley 1998, 2007;Chapelle et al 2005). The comparable that periodic O 2 exposure is an important component of this redox variability in anaerobically active shallow groundwater environments (Rolfe et al 1978;Krieg and Hoffman 1986;Kato et al 1993;Marschall et al 1993;Fridovich 1998). Likewise, mineralization of DCE and VC at DO concentrations below the current field standard for nominally anoxic conditions (0.1 to 0.5 mg/L) can be substantial (Bradley and Chapelle 1996, 1997, 1999a, 1999b, 2000aBradley et al , 1998cSingh et al 2004;Gossett 2010) in groundwater and surface water systems.…”

Coordinate induction of peroxidase and H2O2-forming nucleoside oxidase in Flavobacterium meningosepticum

“…For example, in a microaerophile, Spirillum voltans, a mutant that had NADH peroxidase activity was much more resistant to H P O P than the parent strain, which had no NADH peroxidase activity [9]. In some anaerobic bacteria, only peroxidase activity but not catalase and superoxide dismutase activity showed correlation with oxygen tolerance [10]. Rhodobacter capsulatus produces catalase-peroxidase and peroxidase, and a catalase-peroxidase negative mutant showed only a slight di¡erence from the parent strain as to the resistance to oxidative stress, suggesting that the peroxidase has an important function in eliminating activated O P molecules in the bacterium [11].…”

Comparison of there anaerobic culture techniques and media for viable recovery of subgingival plaque bacteria

“…They suggest that continuous anaerobiosis is not an urgent requirement during plaque processing, at least if the exposure to oxygen is of short duration as in this study. It has been shown that even strict anaerobes may tolerate some exposure to oxygen (16,27), When strict anaerobes were exposed to room atmosphere for as long as 20-40 min there was a 30-70% reduetion in the colony counts (16).…”