30 results about "Endotoxin Contamination" patented technology

The invention provides a process for the purification recombinantly expressed, self-assembled VLP from the homogenate of a bacterial host, wherein the process can be scaled up to a commercial production scale in a cost effective manner. The process comprises a first chromatography using an anion exchange matrix, a second chromatography using hydroxyapatite and, optionally, a size exclusion chromatography. VLP preparations obtained by the process of the invention are essentially free of endotoxin contaminations.

The present invention discloses a DTE immobilized nano microsphere and a preparation method thereof, and a method for producing D-psicose based on the DTE immobilized nano microsphere. Two geneticallyengineered bacteria are constructed in the method for one-step synthesis of the DTE immobilized nano microsphere. Firstly, a D-tagatose-3-epimerase gene (dte) is fused to a 5' end of a PHA synthetasegene (phaC) through a fragment of linker by a gene fusion method to obtain a dte-linker-phaC recombination gene fragment, the gene fragment is respectively transformed into food-grade expression hosts of L.lactis NZ9000 and non-endotoxin-contaminated ClearColi for inducible expression, and a PDE nano microsphere with DTE on surface can be synthesized in recombinant L. lactis or recombinant ClearColi cells, so that the DTE is effectively bonded to the surface of the nano microsphere, forming the immobilized DTE and achieving DTE production and immobilization in one step.

The invention provides a porcine circovirus type 3 Cap protein, nucleic acid, virus-like particles, vaccines and preparation methods and applications, and relates to the technical field of molecular biology. The porcine circovirus type 3 Cap protein provided by the invention has such as SEQ The protein with the amino acid sequence shown in ID NO.2 can be expressed solublely in a yeast expression system, and effectively improves the yeast expression efficiency of porcine circovirus type 3 Cap protein. Moreover, the porcine circovirus type 3 Cap protein provided by the present invention can be self-assembled into virus-like particles, and the vaccine prepared by using the virus-like particles has the characteristics of both cellular immunity and humoral immunity. Immunological related experiments show that the immune effect is very good. it is good. The use of yeast expression system to express porcine circovirus type 3 Cap protein has the advantages of low production cost, simple production process, a large amount of target protein can be obtained through high-density fermentation, and no endotoxin pollution, and can be used for large-scale production.

Methods for purifying fucoidan in extracts from brown seaweed are disclosed. In particular, methods of purifying fucoidan in the extract to remove heavy metal ions, bacterial and endotoxin contaminants, and other impurities are disclosed. The methods include the use of a chelating agent, selective precipitation, and filtration.