Mechanisms in the Microbial Oxidation of Alkanes 461 



SUBSTRATE PRODUCT 



OCTADECANE 1 = 1 Mixture of : 



CH3(CH2 ),6C00CH2(CH2)i6CH3 



CH3 ( CH2 )|4 COOCH2 (CH2 )|6 CH3 



HEXADECANE CH3 (CH2 )i4 COOCH2 (CH2)i4 CH3 



TETRADECANE CH3 (CH2 )i4 C00CH2(CH2)i2 CH3 



DODECANE CH3 (CH2 )i4C00 - X 



Fig. 5 Esters obtained from culture fluids of Micrococcus growing on al- 

 kane substrates. From Stewart et al. (13) . 



ORIGIN OF CARBON IN ACID MOIETIES OF ESTERS 

 FROM BACTERIAL ALKANE OXIDATIONS 



Esters produced by alkane utilizing micrococci are predom- 

 inantly palmitates regardless of the length of n-alkane used as 

 substrate as shown in Figure 5 [from Stewart and Kallio, (13) ]. 

 To estabhsh the origin of the carbon skeletons of palmitic acid in 

 cetyl palmitate ( from hexadecane ) and myristyl palmitate ( from 

 tetradecane) hexadecane-1-C^^ and tetradecane-1-C^* were sup- 

 plied to cultures of the organisms in otherwise mineral media. 

 Esters were isolated, saponified and the palmitic acid and alcohol 

 moieties were recovered. In each case carbon atoms 1, 2, 3, 

 and 4 of palmitic acid were isolated (as benzoate) and C^^ ac- 

 tivities of each carbon atom were deteniiined. 



Data for the palmitic acid from cetyl palmitate are shown 

 in Figure 6 and leave Httle doubt that the ester is formed by 

 condensation of two 16 carbon units derived from the hexade- 



Activity of Fragment I486 1161 



^'^""^ C^^^IcT-C-C-C-COOH 



II 



% activity ' 65~^ 52 



Fig. 6. Distribution of C^* in palmitic acid moiety of cetyl palmitate 

 isolated from cultures of Micrococcus sp. utilizing hexadecane- 1-C^* for 



growth. 



