IQ2 LABORATORY GUIDE IN BACTERIOLOGY 



salt-rising bread dough, and carbon dioxid is liberated, 

 which causes the bread to rise. 



SECTION 6 

 A STUDY OF TORULAE 



Experiment i 



1. Transfer from laboratory cultures to wort agar. 



2. Make stains, and transfer to all the other media. 



3. Make descriptions of these organisms, and note 

 the differences from yeasts. 



Experiment 2 



1. Prepare three plates of wort agar. 



2. Expose these to t^e air in different places. 



3. Incubate at 25 C. 



4. After 48 hours fish ror torula colonies, transfer 

 these to all the media, prepare stains, and describe the 

 cultures. Inoculate fermentation tubes with carbo- 

 hydrates, and inoculate gypsum blocks. Some torulae 

 produce gas from lactose; the true yeasts do not, 

 Torulae do not form spores. 



SECTION 7 



A STUDY OF ACETIC-ACID BACTERIA 

 EXERCISE I 



1. Secure some old vinegar with a film on top. 



2. Prepare a suspension of the film in sterile water. 



3. Plate out in wort agar, and incubate at 25 C. 



4. Transfer the colonies to slant agar. 



5. Inoculate flasks containing about 50 c.c. wort and 

 i per cent alcohol with the cultures. 



