Immobilization of Paenibacillus polymyxa with biopolymers to enhance the production of 2,3-butanediol.

Background: Paenibacillus polymyxa, is a Gram-positive, plant growth promoting bacterium, known for producing 98% optically pure 2,3-butanediol, an industrially valuable chemical for solvents, plasticizers and resins. Immobilization of Paenibacillus polymyxa has been proposed to improve the cell stability and efficiency of the fermentation process, reduce contamination and provide easy separation of butanediol in the culture broth as compared to conventional bioprocesses. This research aimed to explore the potential of Paenibacillus polymyxa with immobilization technique to produce 2,3-butanediol.

Results: We investigated different immobilization methods with natural biopolymers like alginate, chitosan and carrageenan-chitosan-based immobilization. These methods were further investigated for their immobilization efficiency and yield in 2,3-butanediol production. Carrageenan-chitosan beads enabled a higher cell concentration and demonstrated superior cell retention to calcium-alginate-chitosan beads. Carrageenan-chitosan immobilization preserved 2,3-butanediol production in bacteria and increased the product formation rate.

Conclusion: Carrageenan-chitosan immobilization enables non-pathogenic Paenibacillus polymyxa to be a capable 2,3-butanediol producer with increased product formation rate, which has not been previously reported. This novel strategy offers promising alternative to traditional fermentation processes using pathogenic strains and can be further applied in co-cultivations for metabolite production, wastewater management and bioremediation.