The disclosure discloses recombinant Bacillus subtilis for synthesizing guanosine diphosphate fucose and a construction method and application thereof. The recombinant Bacillus subtilis is obtained by intensively expressing guanylate kinase and nucleotide diphosphokinase genes and expressing exogenous fucokinase and phosphate guanylyltransferase genes in a genome of Bacillus subtilis 168. According to the disclosure, a bacterial strain for synthesizing the guanosine diphosphate fucose is obtained by reconstructing the Bacillus subtilis 168, with a volume of intracellular accumulation up to 196.15 g/L. According to the disclosure, by intensively expressing the guanylate kinase and nucleotide diphosphokinase genes, and enhancing the supply of intracellular GDP-L-fucose composition cofactors, the synthesis of the guanosine diphosphate fucose is promoted. The construction method for the recombinant Bacillus subtilis of the disclosure is simple and convenient to use, thus having good application prospects.

A transport medium for a microorganism is provided. The transport medium includes at least one chaotropic substance, at least one acid, at least one buffer, at least one chelating agent, and at least one detergent. The transport medium is able to inactivate bacteria and viruses at the time of sample collection, stabilize and preserve microbial nucleic acids at ambient temperature for extended periods of time.

The invention relates to a method of culturing mammalian cells expressing a heterologous protein in a perfusion cell culture comprising increasing the potassium concentration and decreasing the molar ratio of sodium to potassium to reduce wasteful cell bleed and to increase protein production. The invention further relates to a serum-free perfusion medium comprising a high potassium ion concentration and a low molar ratio of sodium to potassium and to the use of this medium for use in culturing cells in a perfusion culture during production phase or for reducing the cell bleed volume during production phase.

Provided herein are methods for generating cellular biomass in continuous aerobic fermentation systems. The biomass yield, and the concentration of polyhydroxyalkanoate within the biomass, are each directed to advantageous levels by operating the continuous fermentation system under particular nutrient limitation conditions. Also provided are biomass produced using the provided methods, and animal feed compositions including the provided biomass.

Methods of expanding tumor infiltrating lymphocytes (TILs) using a potassium channel agonist, such as a K.sub.Ca3.1 (IK channel) agonist, and uses of such expanded TILs in the treatment of diseases such as cancer are disclosed herein.

Described herein are methods and compositions related to generation of induced pluripotent stem cells (iPSCs). Improved techniques for establishing highly efficient, reproducible reprogramming using non-integrating episomal plasmid vectors. Using the described reprogramming protocol, one is able to consistently reprogram non-T cells with close to 100% success from non-T cell or non-B cell sources. Further advantages include use of a defined reprogramming media E7 and using defined clinically compatible substrate recombinant human L-521. Generation of iPSCs from these blood cell sources allows for recapitulation of the entire genomic repertoire, preservation of genomic fidelity and enhanced genomic stability.

Methods and compositions for the production of cardiomyocytes and cardiac organoids from the differentiation of pluripotent stem cells in three-dimensional (3D) culture are provided. Rock inhibitor, which has been ubiquitously used as a medium supplement to prevent apoptosis during handling and culture of pluripotent stem cells, compromises the capacity of cardiac differentiation of pluripotent stem cells in 3D culture at the most commonly used concentrations.

A medium with a reduced osmotic pressure containing a basal medium, in which the osmotic pressure is adjusted to 150 to 250 mOsm/kg, is useful for culturing cells.

The present invention discloses a serum-free medium for full suspension culture of MDCK cells and a preparation method of the serum-free medium. The serum-free medium for full suspension culture of the MDCK cells comprises basic metabolic nutrients, nucleotide, vitamins, inorganic salts, a shear force protective agent, a cell clustering resisting agent, a pH buffer agent, a pH indicator, an influenza virus proliferation accelerant and other additives. The preparation method of the serum-free medium for the full suspension culture of the MDCK cells comprises the following steps: 1) preparing a mixed solution: dissolving and mixing raw materials; and 2) regulating pH: regulating the pH of the mixed solution to 6.3 to 6.7, and setting a constant volume to obtain the serum-free medium for the full suspension culture of the MDCK cells. The medium supports the high-density full-suspension culture of the MDCK single cells, greatly shortens a time for educating the MDCK cells from adherent cells into the serum-free full suspension cells, and is applicable to the mass production of biological products, and particularly veterinary biological products.

A non-freezing refrigerated storage liquid for stem cells such as iPS cells, according to an embodiment, comprises: potassium ion species in a range of 30 to 80 mmoL/L; sodium ion species in a range of 30 to 80 mmoL/L, wherein ion-based molar ratio of sodium ion species to potassium ion species (ratio ofNa.sup.+ to K.sup.+) is in a range of 0.5 to 1.3; trolox or its analog at a concentration of 1 to 8 mM; adenine or a salt or derivative thereof at a concentration of 0.1 to 4.2 mM; all of or all but one, two or three of essential amino acids, total content of which is 50 to 200 mg; and non-essential amino acids, total content of which is 50 to 200 mg/L.