30 results about "Endotoxin Contamination" patented technology

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.

The invention provides a multi-copy metallothionein recombinant expression vector and a method thereof for high-efficiency expression of metallothionein, and belongs to the technical field of biological chemistry. The method is as follows: constructing the multi-copy metallothionein recombinant expression vector; converting the constructed multi-copy metallothionein recombinant expression vector in pichia pastoris GS115 or KM71, and screening on a histidine-free culture medium to obtain recombinant bacteria; inoculating the screened recombinant bacteria in a BMGY culture solution, rapidly oscillating for culture, centrifugally collecting bacteria, resuspending with the culture solution, diluting, rapidly oscillating for culture until log phase, adding methanol, and feeding the methanol in batches to continue to cultivate; collecting the bacteria, ultrasonically crushing, collecting supernatant by centrifugation, and separating and purifying the supernatant to obtain the metallothionein. The method overcomes the defects of a traditional metallothionein preparation method, can effectively avoid the waste of a lot of animal resources and bacteria sourced endotoxin contamination, reduces the production cost, and improves the protein yield.

The present invention includes recombinant proteins derived from Clostridium botulinum toxins. In particular, soluble recombinant Clostridium botulinum type A, type B and type E toxin proteins are provided. Methods which allow for the isolation of recombinant proteins free of significant endotoxin contamination are provided. The soluble, endotoxin-free recombinant proteins are used as immunogens for the production of vaccines and antitoxins. These vaccines and antitoxins are useful in the treatment of humans and other animals at risk of intoxication with clostridial toxin.

The invention discloses a method which is feasible in pharmaceutical industry for efficient secretion expressing, preparing and purifying of gene recombinant human metallothionein or analogues thereof. The method is characterized by introducing exogenous genes containing dual-promoters into relevant host yeast cells in transformation or double crossover recombination manner by using plasmid vector pPICZ alpha-MT of exogenous metal sulfur protein genes which contain methanol response element AOX and contain or not contain metal response element MRE to construction expression engineering cells containing the dual-promoters in the methanol yeast host cells. According to the invention, several problems with traditional preparation method of metallothionein, such as high production cost, slaughter and organ harvesting to large number of animals, virus pollution derived from animal, endotoxin pollution derived from bacterial, immunogen of non-humanized protein and the like, are avoided effectively,.

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 invention discloses engineering bacteria for producing gamma-aminobutyric acid and a construction method and application thereof, and belongs to the technical field of bioengineering. The engineering bacteria are obtained by integrating genes of L-glutamic acid decarboxylase and promoters thereof on chromosomes of host bacteria, and the integration loca are located in gamma-aminobutyric acid transaminase genes. The constructed engineering bacteria are good in heredity stability; the expressed L-glutamic acid decarboxylase is high in activity; excess protein expression, especially antibiotic resistant protein expression does not exist, and safety is high. Meanwhile, gamma-aminobutyric acid transaminase of the degradation product gamma-aminobutyric acid is inactivated in the engineering bacteria, so that decomposition of products is avoided in the production process and the yield of products is improved. The raw materials of the engineering bacteria are L-glutamic acid; the gamma-aminobutyric acid is produced efficiently through a biotransformation method, and the produced gamma-aminobutyric acid has no threat of endotoxin pollution, is safe and reliable and can be used in the field of food and heath care products.

The invention discloses a method for removing endotoxin out of polypeptide. The method comprises the steps of dissolving the crude polypeptide in water, and carrying out ultrafiltration concentration to obtain a concentrated solution, sequentially adding an aqueous solution of calcium salt and an aqueous solution of phosphate to adjust the pH value to 8-9; and centrifuging, wherein the crude polypeptide is crude hyaluronidase, crude chorionic gonadotrophin, crude menotrophin or crude corticotropin. The method for removing endotoxin in the production of polypeptide disclosed by the invention; under the premise that the activity and yield of the polypeptide are not affected, endotoxin contaminants contained in the production of the polypeptide are effectively removed; at present, the method has been used in the manufacture of the polypeptide crude drugs, and the content of endotoxin is in line with the requirements of Chinese Pharmacopoeia (2010 Edition).

The invention belongs to the field of biological genetic engineering, and provides a dual-promoter inducible secretable shuttle plasmid. The shuttle plasmid consists of an enzyme cutting Escherichia coli pET-28a plasmid and an enzyme cutting bacillus subtilis pE194 plasmid, wherein a lysozyme-antibacterial peptide functional fragment and an antibacterial peptide gene are inserted into the enzyme cutting Escherichia coli pET-28a plasmid. The invention also provides a method for constructing the dual-promoter inducible secretable shuttle plasmid. The shuttle plasmid is transferred to a prokaryote to express proteins such as toxalbumin, cecropin and the like in a fusion mode without toxicity to a host. The shuttle plasmid constructed by the method can be induced by IPTG or lactose to improve gene expression level; the shuttle plasmid is also suitable for exocrine expression, and a target protein for the exocrine expression is convenient to process and is not polluted by endotoxin; and because the shuttle plasmid has dual functional promoters, different genes can be inserted in appropriate correct directions for gene expression.

The invention discloses a method for preparing inositol by a multi-enzyme reaction system expressed by edible microorganisms. The method has the advantages that strains for the food industry serve asmulti-enzyme expression systems to produce isoamylase, glucan phosphorylase, glucose phosphate mutase, inositol-3-phosphate synthase and inositol monophosphatase, which are required for catalyzing starch and derivatives thereof, so that the possibility of contaminating the inositol by toxic protein, antigenic protein or endotoxin generated by escherichia coli in a production process is avoided fundamentally, a strict and complicated purification process is avoided, and the production cost is reduced.

The invention provides a porcine circovirus 3 Cap protein, nucleic acid, virus-like particles, vaccine, and a preparation method and application of the porcine circovirus 3 Cap protein, and relates tothe technical field of molecular biology. The porcine circovirus 3 Cap protein provided by the invention has an amino acid sequence shown as SEQ ID NO.2, can be expressed in a soluble manner in a yeast expression system, and effectively improves yeast expression efficiency of the porcine circovirus 3 Cap protein. In addition, the porcine circovirus 3 Cap protein provided by the invention can be self-assembled into the virus-like particles, the vaccine prepared by using the virus-like particles has the characteristics of cell immunity and humoral immunity, and immunologic related experiments show that the immune effect is good. The method for expressing the porcine circovirus type 3 Cap protein by utilizing the yeast expression system has the advantages that production cost is low, the production process is simple, and a large amount of target proteins can be obtained through high-density fermentation, has no endotoxin pollution, and can be used for large-scale production.

The invention discloses pichia pastoris with endotoxin removal activity and an application of the pichia pastoris in endotoxin removal. The pichia pastoris with endotoxin removal activity is screenedby high-throughput breeding, and the pichia pastoris is preserved in CCTCC (China Center for Type Culture Collection) with the preservation number being CCTCC NO: M2017723. The invention further discloses the application of the pichia pastoris in the endotoxin removal. Whole cells, cell wall components or fermentation liquor of the pichia pastoris are added to endotoxin polluted feed, food or fermentation liquor, and residual level of endotoxin is reduced to 60% or lower. The pichia pastoris can be applied to the endotoxin removal of products such as feed, food, biological products and the like.

The present invention provides a method of biosynthesizing a recombinant protein containing the biologically active peptide, the pharmaceutical composition containing the recombinant protein as well as the preparation of the recombinant protein. Simply speaking the consecutively multiple copies of the bioactive peptide are replaced in the amino acid sequence of a recombinant protein (so called peptide-protein). Then, a high concentration and high yield of the peptide-protein containing the consecutively multiple copies of the bioactive peptide is produced by the biosafety and edible strain of yeast without any endotoxin contamination.

A point-of-use kit is designed for optically detecting and quantifying bacterial endotoxin by employing specific formulations of Limulus amebocyte lysate (LAL), each formulation designed to optimize results with different sample classes. Kits are pre-certified for use with a variety of environmental, industrial, and clinical samples, each sample category having a unique kit design and containing a unique lysate reagent formulation. Pre-certification transfers time and reagent consuming tasks, such as assessment of sample compatibility and sample effect on reagent sensitivity to endotoxin from the user to the kit producer. A fixed dilution/sample treatment is employed, eliminating the need for a comparative water standard and for a sample positive control. The kit has LAL reagent prepackaged in dry polyethylene capped tubes, which retains reagent shelf life and optical clarity for accurate and reproducible results using a portable spectrophotometer/optical reader.

The present invention relates to a membrane based assay method, device and kit for rapid detection and/or quantification of endotoxins in aqueous solutions and test samples. The kit as per the present invention comprises lipopolysaccharide (LPS) affinity ligand conjugated with gold nanoparticles (GNPs); a membrane device comprising an endotoxin affinity membrane positioned parallelly to one or more layer(s) of a hydrophilic material, which are optionally secured in an enclosure; and optionally comprising an indicator chart for quantification of endotoxins in the sample. The method comprises placing the sample suspected of endotoxin contamination on a surface of a membrane comprised in a membrane device; placing once or more a suspension of LPS-affinity ligand conjugated with GNPs over the same area as the sample placed and detecting the presence of endotoxin if the colour signal appears and based on its intensity quantifying the endotoxin levels.

The invention discloses a method for removing endotoxin in trypsinase. The method comprises the following steps: dissolving a trypsinase filter cake in water, carrying out ultrafiltration concentration to obtain a concentrated solution, sequentially adding a phosphate water solution and a calcium salt water solution, regulating the pH value to 8-9, and centrifugating. On the premise of not influencing the activity and yield of the trypsinase, the method for removing endotoxin in the trypsinase production process effectively removes the endotoxin pollutant contained in the trypsinase production process, and has been applied to trypsinase raw drug production at present; and the endotoxin content conforms to the related requirement.