RIBOFLAVINE 



and riboflavine production, but xylose gave the highest yields of 

 riboflavine, although it resulted in poor growth. Potassium, mag- 

 nesium and sulphate ions were essential for riboflavine production. 

 V. E. Pontovich ^^ claimed to have isolated 2 mg. of riboflavine per 

 g. from the mycelium of Aspergillus flavus, whilst Tanner et al.^^ found 

 up to 1-38 ftg. per ml. in fermentation liquor from Penicillium chryso- 

 genmn. Of 240 moulds isolated from soil and compost, all synthesised 

 riboflavine, especially large amounts being produced by species of 

 Fusarium.^^ 



Recovery 



Various methods have been used to recover riboflavine from fer- 

 mentation liquors. Thus it may be adsorbed on a suitable material 

 such as fuller's earth or florisil, and eluted from the adsorbate with, 

 for example, polyhydric alcohols. ^^ It may be extracted with butanol 

 and then precipitated from the extract by addition of petroleum ether,^^ 

 or impurities may be precipitated from the fermentation liquors by 

 means of acetone, and the riboflavine recovered from the concentrated 

 filtrate by the addition of more acetone. ^^a Spray or roller drying of 

 the metabolism solution from E. ashbyii gave a product containing 0-2 

 to 6-0 mg. of riboflavine per g. of drymatter.^^ A novel method of 

 isolation, devised by Commercial Solvents Corporation,** was to add a 

 soluble reducing agent to the fermentation liquor, such that an E;^ of 

 from — 0-05 to — 0-40 volt was produced, and filter off the precipitate 

 that formed ; this contained most of the riboflavine. Alternatively, 

 the Efi was reduced to at least — 0-096 volt by fermenting the meta- 

 bolism solution anaerobically with such organisms as Streptococcus 

 faecalis, Escherichia coli and Clostridium acetohutylicum and the pre- 

 cipitate that formed was centrifuged off.*^ This may contain up to 

 90 % of the riboflavine present in the fermentation liquor. 



References to Section 5 



1. Seal-test System Laboratories Ltd., U.S.P. 2128845. 



2. Commercial Solvents Corporation, U.S.P. 2202161 ; B.P. 527478. 



3. Commercial Solvents Corporation, U.S.P. 2326425 ; B.P. 553465. 



4. Commercial Solvents Corporation, U.S.P. 2368074 ; B.P. 553903-4. 



5. I. Yamasaki and W. Yositome, Biochem. Z., 1938, 297, 398. 



6. I. Yamasaki, U.S.P. 2297671. 



7. I. Yamasaki, Biochem. Z., 1939, 300, 160 ; Proc. Imp. Acad. 



Tokyo, 1940, 16, 6. 



8. I. Yamasaki, Biochem. Z., 194 1, 307, 431. 



9. A. Saunders and L. S. McClung, /. Bad.. 1943, 46, 575. 



10. R. J. Hickey, Arch. Biochem., 1945, 8, 439 ; R. J. Hickey and 

 Commercial Solvents Corporation, U.S.P. 2425280. 



