INGREDIENTS OF CULTURE MEDIA 271 



Lactobacilli for microbiological assay of vitamins. This product is also of value in 

 the assay of antibiotics. ^^-^^ 



1 Tech. Bull. 147, N. Y. Agr. Exp. Sta., 1928. 10 Biochem. J., 31 :349:i937- 



ch. Bull. 153, N. Y. Agr. Exp. Sta., 1929. ^ J. Bact., 31:595:1936- 



Dairy Science, 15:383: 1932. '^ Ind. Eng. Chem., Anal. Edition: 12:443: 1940. 



a Tech. Bull. 153, N. Y. Agr. Exp. Sta., 1929. ^ J. Bact., 31 :595:i936 



- - 12 In - — 



5 Am. J. Pub. Health, 24: 396 :"F934. "Pub. Health Reports : 66: 327 : 1 951. 



« J. Bact., 35:429: 1938. 15 ind. Eng. Chem., Anal. Edition: n :346: 1939. 



Bact., 31 : 603: 1936. 18 J. Bact., 47:199:1944. 



3 J. Dairy Science, 15:383:1932. 12 ind. Eng. Chem., Anal. Editic 



* J. Dairy Science, 18:647:1935. 13 j_ Qgn. Microbiol., i : 267: 1947. 



5 Am. J. Pub. Health, 24:396:1934. "Pub. Health Reports : 66: 327 : i 



li 



_. Bact., 36:201:1933. "Science, 98:69:1943. 



8 Biochem. J., 32:1262:1938. 



BACTO-MALT EXTRACT (B186) 



Bacto-Malt Extract is a useful ingredient of culture media designed for the 

 propagation of yeasts and molds. This product was used by Thom and Church^ 

 in the preparation of "wort" medium as originally described by Reddish.^ Bacto- 

 Malt Extract Broth, as discussed on page 242, is a complete dehydrated medium 

 and duplicates the medium of Thom and Church. 



Bacto-Malt Extract is employed in the preparation of Bacto-Malt Agar, a 

 widely used medium for the detection and isolation of yeast and molds from 

 dairy products, food and other materials. This medium is discussed in detail on 

 page 65. Partansky and McPherson^ used Bacto-Malt Extract, in conjunction 

 with Bacto-Yeast Extract and Bacto-Agar for the cultivation of molds in their 

 laboratory method for testing mold resistant properties of oil paints. 



1 Thom and Church: The Aspergilli, 1926. 3 Ind. Eng. Chem., Anal. Edition: 12:443: 1940. 



a Abst. Bact., 3:6:1919. 



ENRICHMENTS 



The enrichments described in this section are used with liquid or solid basal 

 media to give the complete formulation. The enrichments are of such a nature 

 that they cannot be sterilized with the base medium but must be added under 

 aseptic conditions. Some of the enrichments are sterilized in the autoclave fol- 

 lowing rehydration while others are supplied as sterile solutions of thermo- 

 labile complexes. Some contain a selective agent producing a medium designed 

 for the isolation or cultivation of a certain group of microorganisms. Care must 

 be taken to use the selective enrichments with the exact base medium specified 

 since the selective agent is standardized with the designated medium and the use 

 of a different base would not give the desired results. 



B AGTO-HEMOGLOBIN ( B 1 36 ) 



Bacto-Hemoglobin, prepared from beef blood, is a convenient, readily avail- 

 able enrichment, which may be sterilized in the autoclave. It is prepared 

 according to the procedure described by Spray^ and is recommended for use in 

 media for the cultivation of Neisseria gonorrhoeae. Hemophilus influenzae, H, 

 ducreyi, Pasteurella tularensis, streptococci, pneumococci, etc. 



Bacto-Proteose No. 3 Agar and Bacto-G C Medium Base enriched with Bacto- 

 Hemoglobin and Bacto-Supplement A or Bacto-Supplement B are recommended 

 for the cultural isolation of the gonococcus from all types of gonococcal infections 

 in the male or female. The technique for this procedure is given in detail on 



