ISSN:
1550-7408
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
SYNOPSIS. Paramecium multimicronucleatum has been cultured for 20 years on a medium of salts, vitamins, amino acids, fatty acids, ribosides, and stigmasterol plus a little nondialyzable fraction (NDF) of baker's yeast. Fractionations of NDF identified 2 essentials: (a) in a fraction 〈 100,000 daltons which contained much protein and replaceable by ovalbumin and (b) in a fraction of 〈 300,000 daltons; this fraction contained much polysaccharide, replaceable by glycogen, which is 〉 300,000 daltons. For 2 years now P. multimicronucleatum has grown well with ovalbumin and glycogen replacing NDF. Besides ovalbumin, concanavalin A satisfies the protein requirement; this lectin attaches to sugar residues in glycogen. Studies with a fluorescent dye, PGA-1A, a stilbene derivative, provides further evidence for the polysaccharide requirement. This dye attaches to polysaccharides; when added to glycogen, and this in turn is added to a culture containing ovalbumin, fluorescent blue vacuoles appear within 2–3 h. When dye + glycogen were added to a culture without ovalbumin, no fluorescent vacuoles were found. A protein appears involved in formation of food vacuoles; this fits the pattern for endocytosis described in recent reviews. Besides glycogen, mannan gave good growth. Dextrin and amylopectin gave only fair growth through 7 serial transfers; glucose, maltose and amylose did not sustain growth. Strain 51 of P. tetratrelia, which grows well in NDF medium, grows well when NDF is replaced with ovalbumin and glycogen.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1550-7408.1980.tb04272.x
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