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THE ACTIXOMYCETES, Vol. I 



the various efforts to subdivide the genera 

 into species, were justified. Others were not, 

 especially when new genera were added with 

 insufficient j ustification. 



Gulliermond and Mangenot (1946) sug- 

 gested division of the Actinomycetales into 

 two groups: (a) acid-resistant forms made 

 up of two genera, Actinomyces and Myco- 

 bacterium; (b) nonacid-resistant forms with 

 two genera, Corynebacterium and PJeifferella. 



Bisset and Moore suggested the creation 

 of two separate orders, Streptomycetales 

 and Actinomycetales, in order to distinguish, 

 by the type of branching, the aerobic sporu- 

 lating genus Streptomyces from the parasitic 

 anaeroljic genus Actinomyces. The second 

 order was subdivided, on the basis of type 

 and arrangement of the component cells, 

 into two families: 1. Actinomycetaccae, in- 

 cluding the anaerobic Actinomyces, and a 

 new genus, Jensenia, comprising the "soil 

 diphtheroids"; 2. M ycobacteriaceae , includhig 

 the genera M ycobacterium , Corynebacterium, 

 and Nocardia. 



Thirumalachar (1955) proposed creation 

 of a new genus Chainia, with a type species, 

 C. antibiotica, on the basis of formation of 

 spherical sclerotic granules, in large aggre- 

 gate masses, from the mycelium. This 

 phenomenon is frecjuently observed among 

 Streptomyces species, and hardly warrants 

 creation of a separate genus. Gattani (1957), 

 for example, reported the formation of 

 sclerotic granules by various strains of S. 

 grisevs when grown on certain media. No 

 aerial mycelium is produced under such con- 

 ditions. A hypha thickens; other hyphae sur- 

 round it, resulting in brownish green masses, 

 eventually becoming black. Some of the 

 granules coalesce in pairs or in threes, giving 

 rise to a larger granule up to 75 /x in diameter. 



Baldacci recently proposed (1958) that all 

 the verticil-forming organisms be united 

 into one genus under the name Strepto- 

 rerticillium. The idea of separating all the 

 forms producing primary or secondary verti- 



cils into a separate group was suggested by 

 the writer 40 years ago, and was discarded 

 as hardly advisable. More recently Pridham 

 et at. (1957) created four sections in the 

 genus Streptomyces, under the names Mono- 

 verticillus and Biverticillus, each comprising 

 either straight or spiral-shaped sporophores. 

 Other investigators attempted to bring these 

 forms together into a distinct genus but were 

 dissuaded by the writer. The fact that the 

 composition of the medium greatly influences 

 this manner of sporulation was among the 

 many reasons advanced against the recogni- 

 tion of a separate genus. 



Evidence is gradually accumulating to 

 justify, substantiate, or even enlarge upon 

 the previously established systems of genetic 

 and specific classification. Such evidence is 

 based upon the following four criteria: (a) 

 cell morphology, (b) cell genetics, (c) cell 

 composition, and (d) biochemical activities 

 of the organisms. 



Pridham and Gottlieb (1948) suggested 

 division of the actinomycetes on the basis 

 of their carbon utilization. All the strepto- 

 mycetes tested were able to utilize D-glucose, 

 D-mannose, starch, dextrin, and glycerol, 

 but not erythritol, phenol, the cresols, Na- 

 formate, Na-oxalate, and Na-tartrate. The 

 conclusion was reached that L-rhamnose, 

 raffinose, L-xylose, D-fructose, L-arabinose, 

 and D-mannitol are best for characterizing 

 Streptomyces species, as brought out in Chap- 

 ter 2. This property was utilized by Kuro- 

 sawa, Gordon and Smith, Zahner and Ett- 

 linger, and others. In spite of the valuable 

 information thus obtained, however, the 

 conclusion may be reached that in no case 

 can the utilization of carbon sources serve 

 alone as a major criterion for characterizing 

 actinomycetes. The information is only sup- 

 plementary in nature. 



Gordon and Mihm dixided a total of 676 

 cultures received imder the generic names 

 Streptomyces, Nocardia, and M ycobacterium 

 into groups on the basis of sporulation, as 



