NUTRITION OF SOME MARINE MICROALGAE WITH SPECIAL REFERENCE TO VITAMIN REQUIREMENTS AND UTILIZATION OF NITROGEN AND CARBON-SOURCES

Aspects of the nutrition of 49 isolates (from 7 algal classes) of microalgae from littoral and neritic habitats are presented. The vitamin requirements of 47 isolates are listed and details of thiamine moiety specificity are included for 11 strains. The thiamine requirement among the chlamydomonads examined is spared by thiazole, but is unstable, being lost after a few transfers. Those algae in which the intact molecule is spared by pyrimidine are absolute requirers, retaining the need for exogenous thiamine over several transfers. Notable among this latter group are two isolates of Chlorella sp., which require thiamine and are also able to reduce nitrate. The ability, or lack of it, of most of the isolates to utilize any of 17 different nitrogen sources is examined. Among the green algae, DL-tryptophan, while not necessarily the best amino-N source, is the most widely used. L-Lysine is used by all the Chlamydomonas and Brachiomonas strains examined, but, under the conditions used here, does not promote growth of Chlorella spp. and is toxic for Platymonas/Tetraselmis. Data on the ability to grow in the dark on acetate and glucose is presented for 44 of the strains. Various miscellaneous observations are included in notes on the species. © 1979, Marine Biological Association of the United Kingdom. All rights reserved.