Definitions of bacterial oxygen relationships.

A summary of the conditions to be considered large differences in normal atmospheric pressure by the roundtable was presented by Dr. Carl encountered at different elevations. Lamanna. It was indicated that two entirely A discussion followed in which it was pointed different situations should be covered by any out by Dr. H. W. Seeley and Dr. Norman D. definitions of bacterial oxygen relationships. Gary that the ability of an organism to utilize The first of these is a description of the environoxygen was often difficult to determine, and that ment or atmosphere in which the bacteria can some of the lactic acid bacteria which apparently grow. This could be handled adequately with the did not use atmospheric oxygen to their advanterms aerobic and anaerobic. Aerobic would tage in their metabolism did contain enzymes indicate the presence of air at atmospheric preswhich could transfer hydrogen to oxygen. The sure, whereas anaerobic would apply to the abquestion was also raised as to how one would sence of air. The second situation to be covered classify an organism that damaged itself by the is the metabolic use of gaseous oxygen by living production of hydrogen peroxide in the presence bacteria. Organisms capable of using oxygen of gaseous oxygen. These situations were not would be defined as oxybiontic (oxybiotic)2 and resolved in the discussion. It was concluded, howthose unable to use oxygen as anoxybiontic ever, that the fact of oxygen utilization in itself (anoxybiotic). should not be a basis for calling an organism Agreement was quite general on the suggested aerobic. use of the terms aerobic and anaerobic. Mr. V. Dr. L. S. McClung and Dr. L. DS. Smith beB. D. Skerman believed that the term aerobic lieved that the terms discussed were not adequate should apply not only to air but also to any gas to define some of the clostridia and other bacteria mixture containing 21 per cent by volume of which have been called microaerophilic. Since oxygen. It would not be reasonable to set the air the derivation of the term microaerophilic does pressure required for aerobic growth because of not describe the situation encountered when clostridia grow aerobically without oxygen enter1 A roundtable discussion on the oxygen relaing into cellular metabolism, it was suggested tionships of bacteria was held on the evening of that a term other than microaerophilic be used May 4, 1954, at the Society of American Bacto desr othes oranism.i The termsox teriologists meeting in Pittsburgh, Pennsylvania. Several persons had been invited to participate tolerant, oxysensible, and aerotolerant were proby Richard H. McBee, the convener. The majority posed. Aerotolerant received the greatest support of those invited to participate were present, as im the ensuing discussion. were several others who were interested in the Dr. N. R. Smith believed that it would be topic. logical and possible to change the description in 2 The terms oxybiotic and anoxybiotic were used Bergey's Manual of some of the clostridia from by Weinland to define respiration with and withmicroaerophilic to anaerobic, aerotolerant. Dr. out gaseous oxygen by Ascaris (Weinland, E. Lamanna called attention to the fact that upon 1906 tber den anaeroben (anoxybiotischen) .. Abschnitt der intermedicaren ch mischen Procritica examination organisms called microzesse in der Puppen von Calliphora. Z. Biol., aerophilic often were found to require for the 48, 87-140). The change in spelling is that of later initiation of growth, or optimal growth, greater workers. than atmospheric concentrations of carbon di-