CLASSIFICATION OF BACTERIA 23 



Family V. BACTERIACEAE. Kod-shaped cells without endo- 

 spores. Usually Gram -negative. Flagella when present 

 peritrichic. Metabolism complex. 



TRIBE A. CHROMOBACTEREAE. 



These are water bacteria forming red or violet pigment. Genera : 

 1. Erythrobacterium (red pigment, e.g. B. prodigiosus), 2. Chromo- 

 bacterium (violet pigment). 



TRIBE B. ERWINEAE. 

 Plant parasites. Genus : 3. Erwinia, 



TRIBE C. ZOPFEAE. 



Gram -positive, copious growth. Not attacking carbohydrates. 



Genus 4. ZOPFIUS. Long rods and chains. Motile. Proteus- 

 like growth. Gelatin not liquefied and carbohydrates not 

 attacked. 



TRIBE D. BACTEREAE. 



Gram -negative, copious growth. Attacking carbohydrates with 

 acid, and often gas, formation. 



Genus 5. PROTEUS. Highly pleomorphic rods and filaments. 

 Actively motile. Amoeboid colonies. Liquefy gelatin, de- 

 compose proteins, ferment glucose and sucrose. Gas C0 2 

 only. 



Genus 6. BACTERIUM. Often motile. Earely liquefy gelatin. 

 Most attack hexoses. often with gas formation (C0 2 + H 2 ). 

 Typically intestinal parasites of man and animals. (B. coli, 

 B. typhosus.) 



TRIBE E. LACTOBACILLEAE. 



Gram -positive, non -motile. Attack carbohydrates with pro- 

 duction of lactic acid (gas, C0 2 ). Growth poor. 



Genus 7. LACTO BACILLUS. 



TRIBE F. PASTEURELLEAE. 

 Gram -negative rods, bipolar staining. 



Genus 8. PASTEURELLA. Parasitic. Gelatin not liquefied. 

 Carbohydrate fermentation slight, no gas. (B. pestis.) 



TRIBE G. HEMOPHILEAE. 



Minute parasitic forms growing only in presence of haemoglobin, 

 serum, etc. 



