CATALYSIS: THE GUIDE OF LIFE 135 



all-trans pigment still predominates. Theoretically, each possible 

 stereoisomer must be present in such an equilibrium mixture if 

 only in minute quantity. 



"The chemical characteristics of the stereoisomers of a given 

 carotenoid are very similar, but fortunately the adsorption affini- 

 ties are highly dependent on configuration, perhaps more so than 

 any other known physical property. Therefore, the Tswett method 

 of chromatographic adsorption is the only effective technique for 

 the separation and study of the stereoisomers. 93 " 



It appears that many biologically important compounds may 

 have superimposed upon their basic chemical structure physical 

 or physicochemical impressions or distortions which can affect 

 their specificities in the catalytic field of activity. While every 

 substance has a chemical structure, this does not preclude the 

 simultaneous formation of a superstructure in the case of compli- 

 cated molecules or molecular groups. 



In cultures of Hemophilus influenzae, Escherichia coli, and Strep- 

 tobacillus moniliformis, the germination of "large bodies" has been 

 observed, and the descendants of these "L type" colonies, instead of 

 resembling the parent organism, are similar in both morphology and 

 development to the pleuropneumonia group of organisms. Such "L 

 type" colonies come from strains which are rare in most species, but 

 they were also observed in cultures of a Flavobacterium, of Bacteroides 

 funduliformis, and of the gonococcus, and have been isolated in pure 

 cultures from the two former. L. Dienes 94 believes that they represent 

 a variant type, in which case the variability of bacteria extends much 

 further than is commonly supposed. E. Kleinberger (references in 

 Dienes' paper) thought that they represented symbionts, a view that 

 Dienes opposes. The question is not finally decided. 



Speaking of the enzymatic synthesis of polysaccharides, M. Stacey 95 

 states: "There is good evidence for the theory, here advanced for the 

 first time, that the synthesizing enzyme remains in combination with 

 the polysaccharide it has synthesized, and there is progressively built 

 up a complex macromolecule in which comparatively short polyglucose 

 chains are 'cemented' together by a nucleoprotein. In the case of one 

 dextran from Betabacterium vermijorme (Ward-Meyer), the aggre- 

 gating process can go on until the macromolecule is so large that it 

 settles out of the solution in the form of granules. The separation of 

 granular synthetic starch takes place in precisely the same manner and 

 the product contains significant amounts of a nitrogenous constituent 

 which could only come from the phosphorylase preparation." 



Evidence that bacterial catalysts direct the formation of specific 



