502 



APPENDIX 



that further definition of optimal growth requirements would be a 

 worthwhile endeavor, 



Rhodospirillum rubrum. 



Stock cultures are maintained as stabs in a medium containing 

 O.S^c yeast extract (Difco), 0.3?c Bacto-peptone and l,5?c agar in de- 

 ionized water, 



A, Synthetic liquid medium. After Ormerod, Ormerod and Gest, Arch. 

 Biochem. Biophys., 94, 449 (1961), 



Stock Solutions 



1. Basal salt solution: 

 Deionized water 

 MgS04 • 7 H20 

 CaCl2 • 2 H2O 

 FeS04 • 7 H2O 

 Ethylenediamine tetraacetic acid 



(dissolve separately and adjust 



pH to 6.8 with NaOH) 

 Trace elements solution 

 Deionized water to 1 liter, 



2. Trace elements solution: 

 MnS04 • 4 H2O 

 H3BO3 



Cu(N03)2 • 3 H2O 

 ZnS04 • 7 H2O 

 Na2Mo04 • 2 H2O 

 Deionized water to 1 liter, 



3. Phosphate solution: 

 KH2PO4 

 K2HPO4 



Deionized water to 1 liter. 



4. 207c DL-malic acid, pH adjusted to 6.8 with NaOH 

 (stored in deepfreeze). 



5. 20% L-glutamic acid, pH adjusted to 6.8 with NaOH 

 (stored in deepfreeze). 



6. Biotin stock solution containing 10 mg per 100 ml of 50% 

 ethanol; dilute 1:20 before use (stored in deepfreeze). 



