CHEMOTAXONOMIC EVIDENCE FOR THE SIMILARITY BETWEEN BOTRYOCOCCUS-BRAUNII L RACE AND BOTRYOCOCCUS-NEGLECTUS

The hydrocarbon distribution patterns of nine strains of the green alg a Botryococcus originating from four lakes and one pond are reported f rom GC-mass spectrometric analyses; they complement previously publish ed investigations on Botryococcus braunii. Seven strains from four dif ferent origins (Australia, Bolivia, England and Portugal) contain very -long-chain hydrocarbons, mainly dienes and trienes, odd-carbon-number ed, ranging on the whole from C-23 to C-33; these compounds are charac teristic of the A chemical race of B. braunii. Depending on the strain , a C-27, C-29 or C-31 prevalence is observed. In the Australian strai ns, the presence of n-C-29 and n-C-31 trienes exhibiting two conjugate d double bonds in the midchain in a cis, trans configuration is report ed for the first time in this alga. Two strains of Botryococcus neglec tus isolated from a water sample collected in an Indian lake produce t rans,trans-lycopadiene as the main hydrocarbon; this acyclic tetraterp enoid is typical of the L chemical race of B. braunii. This result str ongly suggests that B. neglectus and B. braunii L race constitute the same taxa. The hydrocarbon contents vary from about 28% of the dry wei ght in the English strain to less than 0.1% in the Indian ones. Copyri ght (C) 1997 Elsevier Science.