Original paper
The Cultural Requirements of the Prasinophyceae
Ricketts, T. R.
Nova Hedwigia Band 25 Heft 3-4 (1974), p. 683 - 690
9 references
published: Nov 30, 1974
DOI: 10.1127/nova.hedwigia/25/1974/683
ArtNo. ESP050002503009, Price: 29.00 €
Abstract
1. The cultural requirements of twenty-seven marine and fresh water members of the Prasinophyceae have been examined in non-defined and defined media. 2. The five axenic freshwater species all grew well on a variety of media, including a newly formulated synthetic medium. Good growth was also produced on media which had been solidified with agar. These algae had no vitamin requirement for growth. 3. The twenty-two marine species divided into two groups based on their growth characteristics. The first of these, containing eight members drawn largely from the related genera Platymonas and Prasinocladus, grew well in axenic culture in Erdschreiber, ASP2 (Provasoli et al., 1957), and S50 (Droop, 1958) media, as well as on the first two media solidified with agar. They had no vitamin requirement for growth. The second group, containing thirteen members, were algae for which attempts at producing axenic cultures had been unsuccessful. They would grow well in Erdschreiber media in bacteria-containing culture. About half would grow well on ASP2 medium, whereas only a small proportion would grow in S50 medium. None would grow on Erdschreiber or other media solidified with agar. The use of agarose in place of the agar produced similar results in those species examined. The lack of growth on media solidified with agar does not seem to be due to the presence of soluble inhibitors of growth present in the agar. 4. Ten marine species in the second group displayed growth in ASP2 medium and, of these, only eight showed good growth. Seven of the latter (and the axenic marine Asteromonas propulsa) proved to have a vitamin requirement. 5. The algae, Micromonas pusilla, M. squamata, Pyramimonas obovata, Heteromastix longifilis and Heteromastix sp. (P198) all showed a requirement for vitamin B12 and thiamine in non-axenic culture. Heteromastix sp. (P198) and M. pusilia also had an additional requirement for thymine. The latter alga showed improved growth in the presence of pantothenic acid. Asteromonas propulsa had a high requirement for biotin and thymine, and thiamine improved growth. Inositol was strongly inhibitory.
Keywords
freshwater species;agar;synthetic medium;algae;vitamin requirement;genera;agar