Compositions and methods are provided comprising acetolactate decarboxylase (ALDC) enzyme variants having higher specific activity. Composition and method are provided where the ALDC variants are used in combination with metal ions to further increase stability and/or activity.

Methods and compositions for modifying glycans (e.g., glycans expressed on the surface of live cells or cell particles) are provided herein.

Among the various aspects of the present disclosure is the provision of a media for cryopreserved cells and methods of making and using same. An aspect of the present disclosure provides for a cell media formulation comprising (e.g., for day 0) one or more components selected from: MCDB 131; Glutamax; P/S; BSA; Glucose; ZnSO4; an enzyme for digesting DNA (e.g., DNASE1); and/or an apoptosis inhibitor (e.g., BI-6C9).

The invention provides tissue culture system for primary cells (e.g. normal mammalian primary epithelial progenitors). This system includes: a) a serum-free, chemically defined cell culture media; and, b) methods for isolation and in vitro long-term propagation of primary cells (e.g. primary epithelial cells). Primary cells so isolated and cultured can be kept undifferentiated and proliferate for many weeks (>15 weeks) or population doubling (>35 PD) without senescence, or any detectable genetic alterations. Upon changing media/culture conditions, these cells can be induced to differentiate. The invention also provides methods to transform normal primary cells so cultured into “cancer stem cells.” The genetically defined cancer stem cell tumor model mimics the behavior of the disease closely, e.g., the cells are invasive, hormone responsive and metastatic when injected into mice. The tumor cells express genes that are specific to cancer stem cells identified in patient samples.

The present invention relates to a chemically defined medium for eukaryotic cell culture, comprising water, at least one carbon source, one or more vitamins, one or more salts, one or more growth factors, one or more fatty acids, one or more buffer components, selenium and one or more further trace elements and its use in the culture of cancer stem cells, in particular tumorsphere culture of cancer stem cells.

The present invention discloses formulation of a serum-free medium used for human pluripotent stem cells, which comprises the following raw materials: inorganic salt components, organic components, amino acids and amino acid salts, energy substances and metabolic intermediates, vitamins and antioxidants, proteins and polypeptides, trace elements and chromogenic substances; while the culture process comprises the following steps: selecting a basic formulation, performing combination screening, identifying and evaluating results, and testing a new formulation of culture; and proportioning according to the following methods: adding aforesaid raw materials into 950 ml of water for injection, stirring gently until dissolved, and finally adding 2.438 g of sodium bicarbonate, and stirring gently until dissolved, and then adding 1 liter of water for injection, adjusting the pH to the desired value with 1 mol/L sodium hydroxide solution or 1 mol/L hydrochloric acid solution, finally filtering sterilized with 0.1 μm diameter filter under positive pressure, and storing the medium solution in dark place at 2° C.-8° C., the invention solves the problem of high cost of domestic import of serum-free formulation.

The disclosure features methods and compositions for differentiating stem cells into hematopoietic stem and progenitor cells (HSPC) and/or Natural Killer (NK) cells. The methods and compositions described herein are used to differentiate stem or progenitor cells having at least one gene-edit that is maintained in the differentiated cell. Also provided are differentiated cells produced using the methods and compositions described herein for therapeutic applications.

In accordance with the present invention, CHO cells expressing a recombinant polypeptide of interest are grown in media where the amino acids, vitamins, phosphate, lipids and/or antioxidant optimization is utilized to manipulate and/or control the protein quality attributes of the polypeptides. Polypeptides expressed in accordance with the present invention may be advantageously used in the preparation of pharmaceutical compositions.

The present disclosure discloses a method for strengthening a biological manganese oxidation using a magnetic field and use thereof. The method includes steps of inoculating a manganese-oxidizing microorganism into a culture medium containing Mn.sup.2+, performing magnetization treatment in a culture process, and then collecting a biogenic manganese oxide. The method includes steps of performing a primary magnetic field treatment at a magnetic field intensity of 0.2-50 mT for 1-5 h when culturing is performed for 6-12 h, continuing culturing after the primary magnetization treatment, and performing magnetization treatment once every other 24 h for culture time of 72 h. A magnetic field is applied to accelerate an oxidation rate of a manganese-oxidizing microorganism to Mn.sup.2+and a biological manganese oxidation rate is respectively improved by 36.4% and 23.8% under an action of an alternating magnetic field or a constant magnetic field within 72 h.

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.