Lysosomal enzymes produced by immobilized Tetrahymena thermophila

Summary

The ciliated protozoon Tetrahymena thermophila was immobilized for production of secreted lysosomal enzymes in two ways. Cells entrapped in solid Ca-alginate spheres survived but were unable to grow and multiply. However, when encapsulated in hollow Ca-alginate spheres Tetrahymena multiplied well, reaching 0.9 × 10⁷ cells/ml. These immobilized cells secreted large amounts of lysosomal enzymes when the medium was changed daily. This system was transferred to a reactor scale using a conical bubble column reactor for semicontinuous cultivation of the encapsulated cells. Under these conditions α-glucosidase, β-glucosidase, β-hexosaminidase and acid phosphatase were produced for at least 4 weeks. The hollow spheres were stable for 3 months and contained living and secreting Tetrahymena cells during this time. Immobilized T. thermophila cells can thus serve as a good source for production of commercially interesting enzymes.