The invention relates to a method for the protein enrichment of a heterotrophically cultured microalga, the microalga being of the genus Chlorella, even more particularly Chlorella protothecoides, characterized in that it comprises: a first step directed toward limiting the ammonium supply so as to obtain a microalgal biomass with a protein content of less than 50% expressed as N.6.25, preferably less than 30%, more preferentially between 20 and 25%; a second step in which the ammonium supply in the fermentation medium is increased so as to obtain a protein content of greater than 50%, preferably greater than 60%, more preferentially greater than 65%.

A feedback control mechanism for a fermentation of yeast cells to make recombinant proteins uses a respiratory quotient measurement which adjusts the levels of oxygenation and/or fermentable sugar feed. The feedback control mechanism permits well controlled cultures that produce good amounts of product while avoiding toxic accumulation of ethanol. Additionally, recombinant proteins so produced have excellent qualitative properties, such as excellent homogeneity and proper inter-subunit assembly.

A feedback control mechanism for a fermentation of yeast cells to make recombinant proteins uses a respiratory quotient measurement which adjusts the levels of oxygenation and/or fermentable sugar feed. The feedback control mechanism permits well controlled cultures that produce good amounts of product while avoiding toxic accumulation of ethanol. Additionally, recombinant proteins so produced have excellent qualitative properties, such as excellent homogeneity and proper inter-subunit assembly.

The present invention relates to methods of upregulating the high mannose glycoform content of a recombinant protein during a mammalian cell culture by manipulating the mannose to total hexose ratio in the cell culture media formulation.

Provided herein are deglycosylating enzymes that remove a broad range of N-glycans from N-glycosylated proteins. Further provided are methods of recombinantly producing and expressing the deglycosylating enzymes. The presently described deglycosylating enzymes can be used to produce free glycans for characterization, and for prebiotic and immunostimulatory uses. In addition, the presently described deglycosylating enzymes can be used to produce deglycosylated proteins for characterization, to improve digestion, and to reduce immunogenicity.

A variable diameter bioreactor vessel is provided that includes a first vessel section having a first diameter configured to hold a liquid media and biologic material, and a second vessel section having a second diameter that is greater than the first diameter such that the liquid media can be increased from a first volume to a second volume within the vessel.

A variable diameter bioreactor vessel is provided that includes a first vessel section having a first diameter configured to hold a liquid media and biologic material, and a second vessel section having a second diameter that is greater than the first diameter such that the liquid media can be increased from a first volume to a second volume within the vessel.

A technology regarding the production, formulation and use of conditioned media and the factors included therein is disclosed. The conditioned media may be inoculated with animal cells, plant cells and any combination thereof. The inoculations may occur simultaneous or at different times. Cells retrieved from different areas of the animal and/or the plant may also be cultured together to form conditioned media and associated growth factors.

A technology regarding the production, formulation and use of conditioned media and the factors included therein is disclosed. The conditioned media may be inoculated with animal cells, plant cells and any combination thereof. The inoculations may occur simultaneous or at different times. Cells retrieved from different areas of the animal and/or the plant may also be cultured together to form conditioned media and associated growth factors.

Covalently cross-linked pilus polymers displayed on the cell surface of Gram-positive bacteria are assembled by class C sortase enzymes. These pilus-specific transpeptidases located on the bacterial membrane catalyze a two-step protein ligation reaction—first, cleaving the LPXTG motif of one pilin protomer to form an acyl-enzyme intermediate, and second, joining the terminal threonine to the nucleophilic lysine residue residing within the pilin motif of another pilin protomer. Informed by the high-resolution crystal structures of corynebacterial pilus-specific sortase (SrtA) and by developing structural variants of the sortase enzyme whose catalytic pocket has been unmasked by activating mutations, we have developed new reagents capable of forming isopeptide bonds in vitro. The reagents disclosed herein can catalyze ligation of isolated SpaA domains in vitro provide a facile and versatile new platform for protein engineering and bio-conjugation that has major implications for biotechnology.