Extractive Fed-Batch Bioacetone Fermentation with Free Cell and Immobilized Clostridium Saccharoperbutylacetonicum N1-4 in a Large Extractant Volume

This study compared free and immobilized cells with palm oil and hexanol as an extractant in a large volume ratio of extractant to the broth. Fermentation was conducted using TYA (Tryptone-Yeast-Acetate) media, glucose as the substrate and the palm oil, hexanol, and a mixture of hexanol and palm oil with a composition of 1:1 v/v as an extractant in the fermentation with a large volume ratio of extractant to broth of 5. The strain was inoculated as free-suspended cells of C. saccharoperbutylacetonicum N1-4 and immobilized cells in calcium alginate. The best extractant results for the acetone fermentation process in the ratio of extractive fermentation of free cells and immobilized cells were using palm oil as extractants. This extractant harvested acetone well, with the acetone concentration in the extractant at 18.41 g/L in free cell fermentation and 17.07 g/L in immobilized cell fermentation. The maximum total acetone concentration was up to 93.72 g/L broth. Using palm oil as an extractant in a large extractant volume combined with immobilization is an alternative to enhance bioacetone production by effectively reducing the toxicity effect of the products and minimizing nutrient requirements.