58 



THE ACTINOMYCETES, Vol. I 



Figure 25. S. rubrireticuli, a verticil-forming 

 streptomyces (Reproduced from: Shinobu, R. 

 Mem. Osaka Univ. No. 4B: 74, 1955). 



genera, Corynebaderium and Mycobacterium; 

 Actinomycetaceae, with only one genus Acti- 

 nomyces. Kluyver and van Xiel suggested 

 the removal of the family M ycobacteriaceae 

 from the Actinomycetales altogether. 



Langeron suggested the following system 

 of classification of actinomycetes: 



I. Euactinomyces, aerobes. 



II. Cohnistreptothrix, anaerobes, grow 

 poorly on artificial media. 



Figure 26. Anitclla type verticil-forming strep- 

 tomyces (Rei)rodvu'ed from: Shinobu, R. Mem. 

 Osaka Univ. No. 4B: 75, 1955). 



Recent Systems of Classijication 



0rskov, in 1923, divided the actinomy- 

 cetes into three genera: 



1. Cohnistreptothrix , nonseptate mycelium, 

 forming readily sporulating aerial hyphae. 



2. Actinomyces, mycelium septated: 



a. Cultures forming aerial mycelium. 



b. Cultures not forming any aerial 

 mycelium. 



3. Micromonospora, with single spores 

 borne at the ends of branches. 



Jensen (1931) modified the above system 

 by retaining the last genus unchanged, and 

 by designating the first genus as Actinomyces 

 and the second as Proactinomyces, as shown 

 here : 



A. No spores are formed. 



Family Proactinom ycetaceae 

 I. No mycelium is formed. 



a. Acid-fast organisms. 



Genus Mycobacterium 



b. Nonacid-fast organisms. 



Genus Corynebacterium 

 II. Mycelium is formed. 



Genus Proactin om yces 



B. Spores are formed. 



Family .4 ctinom ycetaceae 

 I. Spores in aerial mycelium. 



Genus Actinomyces 

 II. Spores terminally on branches of 

 vegetative mycelium 



Genus Micromonospora 

 Lignieres (1922) divided the actinomy- 

 cetes into three groups: 



1. Actinomyces. Aerobes; mycelial hyphae 

 long, not Ijreaking up into rods. 



2. Brevistreptothrix. Anaerobes; mycelial 

 hyphae short, l)reak up into long rods. 



3. Actinobacillus. No mycelium. Cells rod- 

 shaped. 



I'untoni and Leonardi (1935) divided the 

 actinomycetes into three genera: 



1. Actinomyces Ilarz, a,er()l)ic, producing 

 aerial mycelium and arthroconidia. 



2. Actinobacterium Haas (Cohnistrepto- 



