THE DECOMPOSITION OF CELLULOSE IN SOILS 445 



Bacillus alhidus, n. sp. 



Source : Soil from Tustin, California. 



I. Morphology. 



1. Vegetative cells : Average dimensions 1 x .004 fx. 



2. Endospores : None observed. 



3. Flagella : 1 to 3 in number ; 3 to 5 /x, in length. 



4. Staining reactions : Gram negative. Stain readily with the aniline dyes. 



II. Cultural Characteristics. 



5. Agar strokes, 5 days. 



Beef Agar: Scant, white, spreading growth. 



Potato agar: Abundant, white to grayish white growth, spreading over 



the entire slope. 

 Peptone starch agar: Moderate, white to gray white growth. 



6. Potato cylinders: No growth in 30 days. 



7. Gelatin stab: Scant growth at surface and perceptible growth along 



the track of the needle ; in 5 days. No liquefaction in 30 days. 



8. Beef broth, 5 days. Not clouded. 



9. Litmus milk: Reddened in 7 days, neither coagulated nor digested in 



30 days. 

 10. Plate cultures. 



Ammonia cellulose agar, 15 days. 



Form : Colonies at the immediate surface of the medium are 



round, those located a little beneath the surface are irregularly 



round. 

 Size : 8 to 12 mm. 

 Enzymic zone: Clearing all within colony after 15 days. After 



30 days the colonies show an enzymic zone of 1 to 2 mm. 

 Elevation : Saucer shaped. 

 Chromopenesis : Entire colony is vitreous with the exception of 



a thin, white rim. 

 Internal structure : Indeterminate. 

 Edge : Entire to undulate. 

 Peptone starch agar, 5 days. 



Form : Colonies at the immediate surface are round, those 



slightly below the surface are irregularly round. 

 Size : 2 to 3 mm. 

 Enzymic zone: 1 to 1.5 mm. 

 Elevation : Slightly convex. 

 Chromogenesis : White to Hght grayish white. 

 Internal structure : Coarsely granular ; granules often arranged 



in clumps. 

 Edge: Entire to undulate. 

 Beef agar, 5 days. 

 Form : Round. 

 Size : 1 to 1.50 mm. 

 Elevation : Convex. 



Consistency: Soft; colonies from 10 to 15 days old become brittle. 

 Chromogenesis : By reflected light the colonies are Hght grayish 



white. By transmitted light they appear as semi-transparent 



glistening drops. 

 Internal structure : Granular. 

 Edge : Entire. 



