III. INDUSTIIIAL PREPARATION 333 



II, preparation of riboflavin was started from the residues of butanol-ace- 

 tone fermentation with Clostridium acctolmtijlicum} 



Currently, most of the commercial riboflavin production by aerobic 

 fermentation is probably obtained by biosynthesis with Eremoihecium 

 ashbyii, in submerged culture with continuous aeration and agitation. Pat- 

 ents covering this process were flled by several firms,^- ^ and conditions for 

 the production of riboflavin by Ashbyii have been reported.^ By the use of 

 E. ashbyii grown on solid media (germ rice and germ wheat), the vitamin 

 B2 production on an industrial scale is said to have reached a maximum at 

 20,000 7 per gram (2 %)^ 



A medium containing grain stillage from the ethanol fermentation, 

 cerelose and 1 % peptone is excellent for the cultivation of A . gossypii to 

 produce yields of riboflavin as high as 15,000 7 per gram.^ Studies of ribo- 

 flavin production for commercial preparation by fermentation using the 

 yeast xishbya gossypii upon a pilot-plant scale were made recently.^ Corn 

 steep liquor, peptone, and tankage are suitable nitrogen sources with the 

 fermentation of nutrient mashes.^- ^° 



In 1943, more than 75,000 lb. of crystalline riboflavin were produced 

 from all sources. It is priced at about $100 to 130 per kilogram today, 

 whereas in 1938 the price was $7,945 a pound. ^^ 



Besides the pharmaceutical use, small amounts of vitamin Bo are incor- 

 porated in most bread flours and breakfast foods and in nearly all poultry 

 and hog feeds. 



3 Commercial Solvents Corp., U. S. Pat. 2,202,161 [C.A. 34, 6676 (1940)]; British 

 Pat. 527,478 (April 13, 1939). Chem. Trade J. 113, 26 (1943). 



^Commercial Solvents Corp., U. S. Pats. 2,483,855 (Oct. 4, 1949) [C.A. 44, 2698 

 (1950)], 2,498,549 (Feb. 21, 1950) [C.A. 44, 4630 (1950)]; Hoffmann-La Roche, Inc., 

 U.S. Pat. 2,493,274 (Jan. 3, 1950) [C.A. 44, 2698 (1950)]; Don H. Larson (to Com- 

 mercial Solvents Corp.) U. S. Pat. 2,615,829 (Oct. 28, 1952) [C.A. 47, 834 (1953)]. 



5 C. Chin, Hakko Kdgaku Zasski, 25, 140 (1947) [C.^. 44, 7384 (1950)]. 



« R. Takata, J. Japan. Biochem. Soc. 20, 130 (1948) [C.i. 44, 8063 (1950). 



' K. L. Smiley, M. Sobolow, F. L. Austin, R. A. Rasmussen, M. B. Smith, J. I\L 

 Van Lanen, L. Stone, and C. S. Boruff, hid. Eng. Chem. 43, 1380 (1951). 



8V. F. Pfeifer, F. W. Tanner, Jr., C. Vojnovich, and D. H. Traufler, Ind. Eng. 

 Chem. 42, 1776 (1950). 



9 Merck and Co., British Pat. 640,452 (July 19, 1950) [C.A. 44, 9622 (1950)]. 

 '" For more information on the microbiologic production of riboflavin, see the re- 

 port of D. Perlman, W. E. Brown, and S. B. Lee, Ind. Eng. Chem. 44, 1996 (1952) 

 and Production of Riboflavin by Fermentation in "Industrial Fermentations," 

 (L. A. Underklofer, R. J. Hickey, eds.), Vol. 2. Chemical Pulilishing Co., New York, 

 1954. 

 •' F. W. Tanner, Jr., and V. F. Pfeifer, in "Crops in Peace and War," Yearbook Agr. 

 U. S. Dept. Agr. 1950-51, 763. 



