ZINK UPTAKE BY XEUROSPORA 915 



2. Maximal growth loquircs thai at least 1/30,000 pait of the dry weight of" 

 the Neurospora be composed of zinc, and can be obtained by raising the mould 

 in a culture solution containing 0.08 mgm. or more of zinc/1. 



3. When placed in a culture solution containing inactive zinc more labelled 

 zinc migrates from Neurospora into the solution at 12° than in the aV)sence of zinc. 



4. Cobalt uptake, studied by making use of labelled cobalt (^^Co), amounts 

 only to one-twentieth of the uptake of zinc under corresponding conditions. 



References 



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K. Bernhauer (1928) Biochem. Z. 197, 294. 



D. Bertrand (1948) Atonies 3, 221. 



R. H. Broh-Kahn and I. A. Mirsky (1948) Arch. Biochem. 16, 87. 



J. N. Davidson (1938) Biochem J. 32, 1389. 



R. E. Feeney, H. D. Lightbody and J. A. Garibaldi (1947) Arch. Biochem. 



15, 13. 

 J. W. Foster and S. A. Waksman (1939) J. Bad. 37, 599. 

 G. Ch. Hevesy (1923) Biochem. J. 17, 439. 



C. G. HoLMBERG (1939) Biochem. J. 33, 1901. 



D. Keilin and T. Mann (1940) Biochem. J. 34, 11G3. 

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B. Madsen (1945) Acta Physiol. Scand. 10, 195. 



H. K. Mitchell and M. B. Houlakan (194G) Fed. Proc. 5, 370. 



L. J. MuLLiNS and S. C Brooks (1939) Science, 90, 256. 



F. J. Ryan, G. W. Beadle and E. L. Tatum (1943) Amer. J. Bot. 30, 784- 

 O. Warburg (1948) Schivermetalle. Werner Seengen, BerUn. 



G. Wasiljew (1935) Biochem. Z. 278, 226. 



Comment on paper 94 



Uptake of trace metals of zinc and cobalt, for example, by Neurospora can be 

 convenientlj' studied by making use of labelled metals (paper 94). Maximal growth 

 rate of Neurospora was found to require the presence of 0.08 mgm zinc per litre 

 in the culture solution in which the mould is grown. 



58^ 



