A variety of lower eukaryotes and certain mammalian cells are known to constitutively secrete lysosomal hydrolases. Recent studies in Tetrahymena have shown that phosphatidylinositol 3-phosphate regulates the proper secretion of lysosomal enzymes at the level of phagolysosome formation. We extend these findings by studying the secretion-deficient strain MS-1 of Tetrahymena thermophila, which possess phosphatidylinositol levels similar to wild type.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
June 2007
This work describes the configuration and operation of a bioreactor system especially designed for Tetrahymena cultivation and its use for milk improvement, particularly cholesterol elimination by the action of this cell. An advantage of the proposed method is the re-use of the growth medium; thus, the medium is used twice to provide two batches of Tetrahymena biomass without the need of further inoculation. This makes the procedure of producing the cell biomass faster and more economical.
View Article and Find Full Text PDFAppl Microbiol Biotechnol
March 2007
The nonpathogenic ciliate Tetrahymena thermophila converts cholesterol from foodstuffs into provitamin D compounds in high yields. However, prolonged incubation with wild-type strain CU-399 at high densities results in a final deterioration of milk properties, possibly as a result of secreted hydrolases. Here we attempted to solve this problem using MS-1 Tetrahymena strain, a stable mutant with a low rate of hydrolase secretion.
View Article and Find Full Text PDFBackground: Dihydrofolate reductase (DHFR) and thymidylate synthase (TS) are crucial enzymes in DNA synthesis. In alveolata both enzymes are expressed as one bifunctional enzyme.
Results: Loss of this essential enzyme activities after successful allelic assortment of knock out alleles yields an auxotrophic marker in ciliates.
Background: The non-pathogenic ciliate Tetrahymena thermophila is one of the best-characterized unicellular eucaryotes used in various research fields. Previous work has shown that this unicellular organism provides many biological features to become a high-quality expression system, like multiplying to high cell densities with short generation times in bioreactors. In addition, the expression of surface antigens from the malaria parasite Plasmodium falciparum and the ciliate Ichthyophthirius multifiliis suggests that T.
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