VI. BIOGENESIS 355 



types of bacteria grown in an inositol-free medium for 24 hours contained 

 from 870 7 (Clostridium hutylicum) to 1700 7 {Pseudomonas fiuorescens) of 

 inositol per gram of dry cells. 



The ability of various yeasts to synthesize inositol can be modified by 

 various procedures. It has been shown, ^ for example, that Saccharomyces 

 cerevisiae can be converted from a heterotrophic to an autotrophic habit by 

 successive changes in the medium. If inhibitors are included in the medium^ 

 or if the cells are damaged by ultraviolet light, ^ the ability of the yeast to 

 synthesize inositol is also changed. Torulopsis utilis has been shown^ to 

 synthesize less inositol in an iron-deficient medium than in one containing 

 an adequate amount (0.1 to 3 p.p.m.) of iron. 



The suggestion^" that Aerobacter aerogenes catabolizes m;/o-inositol to 

 CO2, acetate, and pyruvate through the intermediate formation of 2-keto- 

 and 1 , 2-diketo-m?/o-inositol, leads one to speculate on the possibility that 

 these metabolic products might in turn be precursors of inositol in this 

 organism. There is as yet no experimental evidence for this speculation. 



B. INOSITOL SYNTHESIS BY HIGHER PLANTS 



A number of studies of the changes in the inositol content of seeds, leaves, 

 and fruits have been made. Although the total inositol content of plants 

 increases during growth, the concentration in the plant tissues may de- 

 crease. For example, it was shown" that there was a higher concentration 

 of inositol in the growing tips of cucurbit and tomato plants than in the 

 mature leaves. In addition it was found'^ that the inositol concentration 

 in the fruits of these plants remained relatively constant or decreased 

 slightly during development. 



The possibility that inositol is synthesized from glucose and glucose 

 derivatives in plants was strengthened somewhat by the observation^^ 

 that the leaves of the rubber plant, Lactuca virosa L., yielded an aqueous 

 extract which, when incubated with glucose for 3 days, gave rise to a sub- 

 stance which appeared to be inositol. It has also been reported^"* that apricot 

 leaves produced inositol when incubated with glucose and glucose phos- 

 phates. 



« L. H. Leonian and V. G. Lilly, Science 95, 658 (1942). 



^ M. A. Eppright and R. J. Williams, /. Gen. Physiol. 30, 61 (1946). 



8 A. M. Webb and J. R. Loofbourow, Biochem. J. (London) 41, 114 (1947). 



9 J. C. Lewis, Arch. Biochem. 4, 217 (1944). 



" B. Magasanik, /. Am. Chem. Soc. 73, 5919 (1951). 



" C. L. Withner, Ain. J. Botany 36, 355 (1949). 



" C. L. Withner, Am. J. Botany 36, 517 (1949). 



" O. Fernandez, G. Izquierdo, and E. Martinez, Farm, nueva {Madrid) 9, 563 (1944) 



[C. A. 40, 4115 (1946)]. 

 " 0. Fernandez, M. de Mingo, and E. Martinez, Farm, nueva {Madrid) 10, 541 (1945) 



[C. A. 43, 4229 (1949)]. 



