GENERAL SYSTEMATIC BACTERIOLOGY 69 



Without flagella and consequently non-motile, Bacterium. 

 With a single flagellum, Pseudomonas. 

 Spiral Bacteria: Spirillum. 



Higher Bacteria: {Cladothrix, Leptothrix, Streptothrix, Actinomyces) 

 The genus Bacillus is further divided as follows: 



Bacilli with one flagellum are named Monotrichic Bacilli or Pseudomonas. 

 Bacilli with one flagellum at each end, Microsporon. 

 Bacilli with a tuft of flagella at one end are called Lophotrichic Bacilli. 

 Bacilli with flagella over the whole body are called Peritrichic Bacilli. 



Orla- Jensen in 1909 proposed a totally new classification of bac- 

 teria. He divided the bacteria into two orders based upon primitive 

 or advanced characteristics, distribution of flagella, etc. In many cases 

 his published descriptions of genera are not very clear, and the con- 

 struction of a key for the differentiation of the forms is correspond- 

 ingly difficult. The following key will indicate differences between 

 most of the genera described. 



Orla- Jensen's Classification of Bacteria (1909) 



Key to Orders and Families 



I. Cells spherical, rod-shaped or spiral. Endospores formed only in a few 

 sulfur-free spirilla. When motile, mono-or lophotrichous. Tj-pically 

 water bacteria. Secure energy almost exclusively by oxidative processes. 

 Many develop poorly on laboratory media because organic substances are 

 present in too concentrated a form. 



Order I. Cephalotrichinae 

 A. Bacteria not in thread like filaments, no tendency to branch or produce 

 mycelial growth: 



1. Bacteria not containing sulfur or bacteriopurpurin: 



a. Obligate aerobes, oxidizing carbon, hydrogen, or nitrogen 



compounds without production of noteworthy amounts of 

 unoxidized split products. 



Family 1. Oxydohacteriaceae 



b. Luminous and fluorescent bacteria. 



Family 6. Luminibacteriaceae 



c. Active reducing organisms, facultative, all spiral forms re- 



ducing sulfates. 



Family 7. Reducibacteriaceae 



2. Bacteria containing sulfur or bacteriopurpurin: 



a. Containing no bacteriopurpurin. 



Family 3. Thiobacteriaceae 

 h. Containing bacteriopurpurin. 



Family 4. Rhodobacteriaceae 

 B. Bacteria tending to branch, to form filaments or to develop a 

 mycelium. 



