I have a few polysaccharides that I would like to use for bacteria cell culture including pectin. I planned to make them into sterile stock solutions and add them to the autoclaved liquid medium. However, they will swell and form gels when dissolved in water which makes it impossible to filter sterilize. Does anyone have suggested ways of sterilizing this kind of polysaccharide? I think autoclave is not preferred since it will degrade the molecules but if anyone has used autoclave on them I'm more than happy to try that!
Thank you in advance!
Such hydrogels are pH dependent, if you shift the pH outside the optimum range they will not solidify allowing for filter sterilization. Also if you use the methylated versions of the polysaccharides they will not form gels.
Hi Robert, thank you very much for your suggestion about pH. Definitely trying it! Robert Adolf Brinzer
Dec.9, 2023
Dear Xieyue,
I don't know what polysaccharides besides pectin you are working with, but most polysaccharides are pretty stable and can be autoclaved. Check that the pH is near neutral, as polysaccharides will be hydrolyzed by the heat of autoclaving at low pH. If you are concerned that the polysaccharides will form gels at high concentrations, you can use lower concentrations, e.g., 5-10%, and autoclave them in the liquid medium you are using. This way, when you add the polysaccharide to the liquid medium, you won't get a dilution effect.
I hope this information helps you.
Bill Colonna
Dept. Food Science & Human Nutrition, Iowa State University,
Ames, IA.
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