Country: United States
Date: January 2006
Can Knox Unflavored Gelatine be substituted for
Agar in a petri dish in order to grow bacteria for our science
No...the reason sea weed derived agar is used is because very few bacteria
can use it as a food source and so it wont be digested. This is not the
case with gelatin.
Gelatin will work but some bacteria secrete proteases that will
hydrolyze or digest the gelatin. The reslt will be holes in the
gellatin where a bacterial colony is growing.
Ron Baker, Ph.D.
It has to have nutrients as well as just gelatin. All living things
need a source of carbon and of protein. There are recipes on line for
making agar substitutes.
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Update: June 2012