Date: Wed, 18 Nov 1998 14:08:55 -0500
From: firstname.lastname@example.org (Michael Christianson)
Phytagel and mosses.
Yes, Phytagel can work with bryophyte culture media. The media are
wonderfully clear, nice for taking pictures.
However, although it is less expensive than agar, when I compared
growth rates of my mosses (Funaria landraces) on media, differing only in
gelling agent, Difco BactoAgar allows faster growth. So I don't use
Phytagel is a gellan gum, now also approved for use in the food
industry (Orbit, the bottled drink with suspended blobs, is gelled with
phytagel). So the stuff Sigma now sells is a little less wonderful that the
stuff they used to sell. 2g/L used to work fine, but no longer (at least
My student uses it to solidify M&S salts based orchid media, and we
use 2.5 g/L to get reproducibly good gel strength. This also works well for
Knop's salts-based moss media. If you are using a medium with very dilute
salts, or with a peculiar pH, you may need more Phytagel -- or may need to
autoclave the gelling agent in half the water, the other medium components
in the other half of the water, and combine right before pouring, to
prevent hydrolysis of the gum at low pH, autoclave pressures and
Michael L. Christianson
Department of Ecology and Evolutionary Biology
University of Kansas
Lawrence, Kansas 66045
Moss-R-Us .... and Toto too!