Bacterial alginate production by fermentation: Integrating molecular and bioengineering strategies

Alginates are linear polysaccharides composed of varying amounts of (1-4)-β-D-mannuronic acid and its C-5-epimer, α-L-guluronic acid. These compounds have a wide range of applications: they are used as food additives and encapsulation agents in biotechnology and have a promising potential for the biomedical field. Currently, commercially produced alginates are isolated from harvested brown seaweeds. Two bacterial genera, Azotobacter and Pseudomonas, are capable of producing alginate and are promising candidates for alginate production by fermentation. Through bacterial alginate production, it may be possible to develop alginates with a wide range of molecular weights and relative monomer content (mannuronic and guluronic). To develop alginates with desired properties and produce them in high yields, different strategies of fermentation have been proposed for bacterial alginate production. This chapter summarizes the current knowledge of the fermentation strategies that have been implemented for the production of alginate, as well as the potential integration of molecular and bioengineering techniques to develop a competitive bioprocess for producing bacterial alginate.