570 



SCIENCE 



[N. S. Vol. XL VI. No. 1197 



A NOTE ON THE AEROBIC CULTURE OF AN- 

 AEROBES AT HIGHER TEMPERATURES 



A POSSIBLE inverse relation between tlie 

 temperature and oxygen tension require- 

 ments of bacteria has been indicated by 

 Eabinowitchi who showed that the minimum 

 temperature requirement of certain sup- 

 posedly ortho-thermophilic organisms refus- 

 ing to grow aerobieally below 50° C. could be 

 reduced at least to 37° C. by anaerobic culture. 

 Her results account for the finding of thermo- 

 philic bacteria as parasites in the human in- 

 testine by MacFadyen and Blaxall.^ 



"We have had no occasion to confirm the 

 work of Eabinowitch as to the anaerobic growth 

 of thermophilic aerobes as lower temperatures 

 but we have taken advantage of the opportu- 

 nity afforded in a collection of obligative an- 

 aerobes to test the converse possibility, that is 

 the aerobic growth of anaerobes at a higher 

 temperature. A successful result would per- 

 haps have provided a simple means of surface 

 culture for purposes of isolation in certain 

 cases but the results were clearly in the nega- 

 tive. 



It does not matter for this purpose that some 

 of these cultures are as yet incompletely iden- 

 tified. The list, showing sources and the 

 identity of the known forms, is to be published 

 shortly in the Journal of Bacteriology in a 

 paper describing our work on the inhibitory 

 action of gentian violet and its application in 

 preventing spurious presumptive tests due to 

 these organisms in the bacteriological examina- 

 tion of water. Cultures of B. hotulinus, B. te- 

 tanus, B. chauvei, B. osdematis maligni and 

 the Ghon Sachs bacillus, were included among 

 the twenty-one. All were free from ferobic 

 contamination, as shown by tests on agar 

 slants at 37° C. although we can by no means 

 be certain that some of the unidentified cul- 

 tures do not consist of more than one species 

 of anaerobic microorganism. 



Media containing 1 per cent, glucose, 1 per 

 cent, peptone and 3 per cent, agar were used 



1 Eabinowitch, ' ' TJeber die thermophilen Bak- 

 terien," Zeitschr. f. Hyg., 1895, XX., 154. 



^MaePadyen and Blaxall, "Thermophilic Bac- 

 teria," Jour. Patlwlogy and Bacteriology, 1896, 

 III., 87. 



both for the anaerobic controls inoculated as 

 shake cultures for incubation at 37° C, and 

 the Eerobic tests slanted for streak inoculation 

 and incubation at 54° C, in a constant tem- 

 perature acetone bath. Three per cent, agar 

 was necessary to withstand the latter tempera- 

 ture for the period of the test, fifteen days. 

 Three separate trials were made as follows : In 

 the first, subcultures were made from stock 

 cultures several days old in deep sterilized beef 

 brain. These could not be considered cer- 

 tainly negative due to the resemblance of the 

 transferred brain to surface growth. In the 

 second trial, subcultures were made from 24- 

 hour glucose broth cultures in the constricted 

 tube and marble device for anaerobiosis.^ 

 Nothing developed on the surface of the 

 slanted agar incubated at 54° C. which could 

 be considered a bacterial growth. This test 

 was repeated with identical results. 



In a fourth test, 24-hour glucose broth cul- 

 tures in constricted tubes were transferred in 

 quantities of 1 c.c. per tube to melted glucose 

 2 per cent, agar at 42° C. and hardened in the 

 upright position as shake cultures. It was 

 thought that if the premise of this study were 

 true, the greatest growth should occur nearer 

 the surface in the test at 54° C. than in the 

 control incubated at 37° C. But no growth oc- 

 curred aerobieally or anaerobically at 54° C. 

 This test was duplicated in method and re- 

 sults. 



The controls at 37° 0. gave vigorous growth 

 within 48 hours in every case as evidenced by 

 the distinct and characteristic colonies or 

 opacity and all but four produced abundant 

 gas. The freedom of the control tests from 

 ffirobic contamination was also proven by fail- 

 ure of growth on plain agar subplants at 

 37° C. 



LiLLLiN Jordan Ellefson, 

 Ivan C. Hall 



Department of Pathology and 

 Bacteriology, 



University op Calipoenia 



3 HaU, ' ' A New Aerobic- Anaerobic Culture 

 Tube," Univ. of Calif. Pub. in Pathology, 1915, 

 II., 147. 



