59 

 activity (Fig. 3-5C) and units of activity per cell (Fig. 3- 

 5B) between days 3 and 5 (mid-to late-exponential growth 

 reflected a rate of enzyme synthesis that was slower than 

 the growth rate since total units of activity (Fig. 3-5D) 

 continued to increase during that time. From days 5 to 7 

 the decline in specific activity reflected a net loss of 

 enzyme activity. 



Discussion 



C. sorokiniana aromatic-pathway enzyme activities 

 appear to be somewhat lower but consistent with those found 

 in higher plants. The S-protein from N. silvestris must be 

 antigenically different from that of C. sorokiniana, since 

 the S-protein specific antibody did not precipitate the 

 protein from Chlorella. Specific antibodies made to PAT and 

 ADH are now available (see Chapter V) to test cross 

 reactions with these proteins from Chlorella. 



Although the coincident DQT and SDH activity peak from 

 the DEAE column which eluted protein from C. sorokiniana 

 extract was only purified through two steps, it is 

 conceivable that further purification would yield a 

 bifunctional S-protein like that found in higher plants. 

 Activities from column fractions indicated that DQT activity 

 was about half that seen for SDH, whereas crude extracts 

 indicated that activities were about equal. Possible 

 explanations would be that (i) more than one protein is 



