Ophryoglenidae 109 



THE CULTURE OF COLPIDIUM CAMPYLUM 



C. V. Taylor, J. O. Thomas, and M. G. Brown, Stanford University 



THE holotrichous ciliate, Colpidium campylnni, was obtained orig- 

 inally in an enrichment culture from spinach procured in the vicinity 

 of Monterey Bay, California, and subcultured in a continuously thriving 

 condition in a sterile tap water extract of common commercial yeast. 



This extract is prepared in the following manner: 450 grams of a com- 

 mercial yeast is mixed with 500 cc. of water, kept at 50 C. for 24 hours, 

 then neutralized with XaOH to a pH of 7.0, filtered, and autoclaved. 



For cultures the filtrate is diluted ten times with tap water, then appor- 

 tioned in 5 cc. amounts into test tubes. Sterile technique is used through- 

 out. Each tube is inoculated with approximately 1000 Colpidia. The 

 resulting growth is vigorous and uniform. 



Under ordinary laboratory conditions pure strains of this holotrichous 

 ciliate, washed free of bacteria, have thrived vigorously for about two 

 years in this convenient and reproducible medium. The temperature 

 variation was around 20 to 22° C. and the light in the laboratory was a 

 north light. 



A CULTURE METHOD FOR COLPODA 



M. S. Briscoe, Storer College 



FINGER bowls are satisfactory vessels for this culture method. They 

 are first sterilized by exposing them to streaming steam. In this way 

 micro-organisms normally present upon the surfaces of laboratory appa- 

 ratus are destroyed. Both moist and dry heat were tried but the former 

 is more efficient. If there is no Arnold steam sterilizer in the laboratory 

 the sterilizing process may be accomplished in some similar apparatus. 

 A temperature of ioo° C, is sufficient to destroy the majority of micro- 

 organisms that may be present. 



With the completion of the sterilizing process, spaghetti, which may be 

 purchased in cans at a grocery store, should be removed from its con- 

 tainer. It should be thoroughly washed so as to remove any other sub- 

 stances that may be present. When all of these have been eliminated 

 place some of the spaghetti in a finger bowl and cover it completely 

 with water. Faucet water is satisfactory. Allow it to stand for several 

 days until a scum forms. It is then ready for inoculation with the 

 organisms. 



The optimum growth temperature for Colpoda is 70 F. At this 

 temperature the organisms appear normally healthy and grow very 

 rapidly. Increases in temperature do not increase the rate of growth 

 and at sufficiently high temperatures growth ceases. The organisms do 

 not thrive when exposed to intense light such as the direct rays of the 



