I have a question about gellan gum (aka Phytagel, Gelrite). Basically, why is it mostly used as a gelling medium for plant tissue culture and not so much in culturing other organisms? In my experience, it works just fine as a gelling medium for use in fungal growth media, with the added advantage that if the culture is going to be examined by microscopy, Phytagel is super-clear and has a high refractive index. Yet most of the papers that I've seen it's used for plant tissue culture, or plant + fungal dual cultures, but hardly ever for fungi or bacteria alone. Any ideas as to why this is?
Phytagel has a higher melting temperature than agar(ose). Hence it is used for the growth of thermophilic prokaryotes such as hyperthermophilic archaea. Otherwise, the preference for agar for most microbiological applications may be related to its price.
Some bacterial species have been cultured on gellan gum-based solid media, e.g., Acidocella aminolytica (1995), Acidocella facilis (1995), Chthonomonas calidirosea (2011), Flavobacterium banpakuense (2011), Flavobacterium compostarboris (2012), Granulicella cerasi (2014), Methylocaldum marinum (2014), Paenibacillus darwinianus (2014), Thermorudis pharmacophila (2015), Virgisporangium myanmarense (2017).
Some bacterial species degrade gellan gum, e.g., Brevifollis gellanilyticus (2013), Roseimicrobium gellanilyticum (2013), Telmatocola sphagniphila (2012).
Hi,
I have used gellan as an alternate culture medium for fungi. However, it is pricey, which may be a reason why many researchers do not admit using it or have not reported using it. In addition to it, agar takes lesser preparation time while Gellan takes a while to be prepared as also rightly pointed out by Prof. Pierre.
Interesting - I've never noticed that gellan takes any more preparation time, unless you count for the fact that many nutrient agars are sold in powdered form while for nutrient gellan, you have to make your nutirent gel from basic ingredients and/or stock solutions.
In terms of price, that may be a factor in terms of microbiological work. However, if you actually need to do imaging work and need something optically clear, your choices are pretty much agarose, Noble agar, gellan, or maybe carrageenan, and I think those are all in a similar price range. Gellan makes up for part of the expense by having the same gel strength at about 40% of the concentration of Noble agar (eg, 0.6% gellan is about as hard as 1.5% Noble agar).
- Badges
- Science topic
- Similar topics
- Biological Science
- Microbiology