OTHER BACTERIA 105 



OTHER AEROBIC AND ANAEROBIC BACTERIA 



The antagonistic action o£ K. pneumoniae against B. anthracis has 

 been reported. Freudenreich (298) found that the filtrate of this an- 

 tagonist repressed the growth of a number of bacteria, including the 

 diphtheria and plague organisms. 



Other aerobic bacteria were found capable of exerting antagonistic 

 effects against one or more organisms, these effects varying considerably 

 in nature and intensity. It is sufficient to mention the action of P. vul- 

 garis against B. anthracis and P. festis; of Ps. aviseftica against B. an- 

 thracis and E. tyfhosa; of Bacterium lactis aerogenes against B. an- 

 thracis and P. festis. B. anthracis is capable of iso-antagonism and of 

 antagonizing certain other organisms, including E. tyfhosa and Bac- 

 terium acidi lactici (786). Certain Myxobacteriales have been shown to 

 be capable of bringing about the lysis of various plant-disease-producing 

 bacteria 3 a thermostable lytic substance, passing through cellophane but 

 not through a Seitz filter, was obtained. Although certain bacteria like 

 Achromobacter lifolyticum were found capable of reducing the patho- 

 genicity of M. tuberculosis, no active cell-free extract could be ob- 

 tained (79). 



M. tuberculosis produces a water-soluble substance, designated 

 phthiocol, which in concentrations of 0.05 to o.i per cent inhibited the 

 growth of various gram-positive and gram-negative bacteria, but not 

 Ps. aeruginosa (568a). 



Bacillus larvae, a gram-negative rod, was found (441) capable of 

 inhibiting the growth of various gram-positive and gram-negative bac- 

 teria. The human and bovine strains of M. tuberculosis were also in- 

 hibited but not the avian strain. The antibiotic was soluble in water but 

 not in organic solvents. It was adsorbed on activated charcoal but no 

 eluent could be found. It was moderately heat stable. Its antibiotic ac- 

 tivity was inhibited by glucose but not by cysteine or sucrose. 



The morphology of one bacterium may be considerably modified by 

 the presence of another. Living cultures of L. bulgaricus influenced the 

 variation of E. coli from the "S" to the "R" phase, inhibited develop- 

 ment of the organism, and even brought about its lysis. No active sub- 



