Gellan gum is produced by a microbial culture and then further processed for commercial applications.
Gellan gum is produced from S. elodea by a pure-culture fermentation process. It is recovered from the ermentation culture with isopropyl alcohol (Doner and Douds, 1995). The thickness and hardness of the gellan gum is determined by acetyl groups present in the gellan gum obtained from the microbial culture.With acetyl groups present, the gel is soft and elastic. Firmer gels are obtained by removing the acetyl groups to some extent by adding potassium, magnesium, calcium, and/or sodium salts).
Thus, gellan gum is produced by a naturally-occurring biological process, and a chemical process is used toextract the gellan gum from the fermentation medium and to formulate the desired thickness of the gum.
The extraction and formulation steps do not alter the identity of the gellan gum produced by the microbialculture, but they do manipulate functional properties (i.e., the thickness and hardness) of the substance.
