476 



Marine Microbiology 



ALTERNATIVE PATHWAYS POSTULATED FOR 

 2- METHYLHEXANE OXIDATION 



Ci - SCHEME 



HOOC 



2- METHYLHEXANE 



/ 



2 -Me. HEXANOIC 



\ 



Cg- SCHEME 



-COOH 

 5-Me. HEXANOIC 



HOOC ^ HOOC 



PROPIONIC + BUTYRIC 



1 



2 ACETIC 



COOH + ACETIC 

 / -VALERIC 



= + ACETIC 



Inspection of these two schemes shows that the Ci-scheme 

 is characterized by the occurrence of 2-methyl-hexanoic and 

 propionic acid, whereas 5-methylhexanoic and i^o-valeric acids 

 are typical for the Ce-scheme. 



MULTIPLE ADAPTATION EXPERIMENTS 



Using the multiple adaptation principle we have investigated 

 whether the 2-methylhexane-grown cells were adapted simultan- 

 eously to 2-methylhexanoic and propionic acids, or to 5-methyl- 

 hexanoic and iso-valeric acids. For comparison, the oxidation rates 

 of the same acids by n-heptane-grown cells were also detennined. 



n-Heptane metabolism by our Pseudomonas strain had been 

 investigated earlier and the pathway was shown to include hep- 

 tanoic, n-valeric and propionic acids by multiple adaptation tech- 



