Provided herein are methods of culturing a microorganism. The method includes providing a container comprising one or more microorganisms and medium, wherein the microorganisms and medium form a start volume. The microorganisms and medium are cultured until the culture reaches a threshold indicator, wherein culturing comprises feeding one or more carbon sources to the culture and wherein the culture is at a threshold volume when the threshold indicator is reached. The method also includes harvesting a portion of the threshold volume to leave a residual volume that is 40% or less of the start volume and adding fresh medium to the container in an amount to return the volume of the culture to the start volume.

A medium for culturing Balantidium ctenopharyngodoni in vitro, method for preparing the medium and method for culture in vitro are provided, which belongs to technical field of in vitro culture of intestinal protozoa. The formulation of the culture medium includes: 100 ml of Ringer's solution, 0.5 g of yeast extract, 1.0 g of proteose peptone, 3-6 ml of fetal bovine serum, 6-10 ml of horse serum, 300-500 μl of Bacillus licheniformis suspension, 200-300 mg of aseptic starch. Culture steps include: inoculating collected Balantidium ctenopharyngodoni into a prepared medium, filling with nitrogen and sealing, culturing at 15° C. for 48-72 hours, then transferring to another fresh medium, cycling back and forth, proliferating the Balantidium ctenopharyngodoni continuously. Balantidium ctenopharyngodoni are capable of achieving cell division and proliferation in the culture medium, and lays foundation for the physiological and experimental ecology research of the Balantidium ctenopharyngodoni.

A method of inducing a generalized immune response, includes administering to a subject an immunologically effective amount of one or more isolated immunogenic peptides comprising an amino acid sequence of SEQ. ID NOs: 1-46, thereby inducing a generalized immune response to infection by a pathogen in a subject. A prophylactic or therapeutic composition for inducing a generalized immune response, includes an immunologically effective amount of one or more isolated immunogenic peptides comprising an amino acid sequence of SEQ. ID NOs: 1-46. A method of distinguishing a subject infected with a pathogen from an uninfected subject, includes detecting an antibody in the subject that selectively binds one or more isolated immunogenic peptides comprising an amino acid sequence of SEQ. ID NOs: 1-46, wherein the presence of the antibody indicates that the subject is infected with the pathogen. A general method to discover broadly protective components for a vaccine is also disclosed.

A method of inducing a generalized immune response, includes administering to a subject an immunologically effective amount of one or more isolated immunogenic peptides comprising an amino acid sequence of SEQ. ID NOs: 1-46, thereby inducing a generalized immune response to infection by a pathogen in a subject. A prophylactic or therapeutic composition for inducing a generalized immune response, includes an immunologically effective amount of one or more isolated immunogenic peptides comprising an amino acid sequence of SEQ. ID NOs: 1-46. A method of distinguishing a subject infected with a pathogen from an uninfected subject, includes detecting an antibody in the subject that selectively binds one or more isolated immunogenic peptides comprising an amino acid sequence of SEQ. ID NOs: 1-46, wherein the presence of the antibody indicates that the subject is infected with the pathogen. A general method to discover broadly protective components for a vaccine is also disclosed.

Methods of preparing mammalian enteroids, and methods producing T. gondii oocysts in vitro and in vivo in heterologous systems, are provided.

Provided herein are methods of culturing a microorganism. The method includes providing a container comprising one or more microorganisms and medium, wherein the microorganisms and medium form a start volume. The microorganisms and medium are cultured until the culture reaches a threshold indicator, wherein culturing comprises feeding one or more carbon sources to the culture and wherein the culture is at a threshold volume when the threshold indicator is reached. The method also includes harvesting a portion of the threshold volume to leave a residual volume that is 40% or less of the start volume and adding fresh medium to the container in an amount to return the volume of the culture to the start volume.

Provided herein are methods of culturing a microorganism. The method includes providing a container comprising one or more microorganisms and medium, wherein the microorganisms and medium form a start volume. The microorganisms and medium are cultured until the culture reaches a threshold indicator, wherein culturing comprises feeding one or more carbon sources to the culture and wherein the culture is at a threshold volume when the threshold indicator is reached. The method also includes harvesting a portion of the threshold volume to leave a residual volume that is 40% or less of the start volume and adding fresh medium to the container in an amount to return the volume of the culture to the start volume.

A stool sample evaluation flotation agent comprising at least 0.01 mol/kg of a first compound which, in a dissolved state, releases anions by a buffer effect to generate and stabilize a neutral pH environment having a pH between 6.0 and 8.0. A method of stool sample examination involving separating endoparasites from a stool sample, the method comprising mixing the stool sample with a flotation agent comprising at least 0.01 mol/kg of a first compound which, in a dissolved state, releases anions by a buffer effect to generate and stabilize a neutral pH environment having a pH between 6.0 and 8.0

Provided is a dried powder of microorganisms, which is highly suitable for processing and has excellent usefulness as one component of various products. The present invention provides: a dried powder of microorganisms, the dried powder exhibiting a brightness of 55 or more and a chromaticness of 18 or less; and a method for producing a dried powder of microorganisms, the method comprising: washing microorganisms at least once with a liquid having an osmotic pressure lower than that of a liquid culture medium for culturing the microorganisms; and drying and heating the microorganisms after the washing to thereby obtain the dried powder of the microorganisms, which exhibits a brightness of 55 or more and a chromaticness of 18 or less.

The present disclosure provides mutant parasites, in particular protozoan parasites comprising a mutation of the trehalose-6-phosphate synthase/6-phosphate phosphatase (TPS/TPP)-like gene of Toxoplasma gondii (herein referred to as Toxoplasma) or a homologue thereof as well as vaccines comprising same.