ConclusionFlocculation and immobilization with chitosan were combinedinto one method to immobilize cells from resuspension and fer-mentation broths. Chitosan is also a carrier suitable for use in astirred tank reactor. Both immobilized cells from cell resuspensionand fermentation broth were reused four times in the stirred tankreactor and showed higher stability than free cells. Immobilizedcells from the fermentation broth showed better operational stabil-ity and were easier to prepare. The industrial process for l-citrullineproduction was established with cells immobilized with chitosan.With cells immobilized from 2000 L of fermentation broth, 733.5 kg