5 results about "Bovine lactoferrin" patented technology

This invention provides an antimicrobial peptide spray, its preparation method, and its application in the prevention and treatment of peristomal skin infections. The spray comprises, by weight percentage, 0.05%-0.5% of a complex antimicrobial peptide, 0.1%-5% of a moisturizing and repairing film-forming matrix, 0.05%-0.2% of a buffer, 0.8%-1.2% of an isotonic regulator, 0.01%-0.5% of a stabilizer, and 0.005%-0.05% of a metal ion chelating agent, with the balance being water for injection. The complex antimicrobial peptide is composed of bovine lactoferrin antimicrobial peptide, sericin oligopeptide, and buckwheat-derived anti-inflammatory active peptide in a weight ratio of (3-5):(2-3):1. This spray possesses four core functions: broad-spectrum antibacterial activity, inhibition of bacterial biofilm, anti-inflammatory and soothing effects, and skin barrier repair. It is less likely to induce bacterial resistance, does not irritate damaged skin around the stoma, and can effectively prevent and treat peristomal skin infections.

The application discloses a complex preparation containing bovine lactoferrin and lyticase and application thereof, and belongs to the technical field of biology. The preparation is composed of bovine lactoferrin and streptococcal lyticase, and both are prepared through a baculovirus-insect cell eukaryotic expression system. Researches show that the complex preparation has a significant synergistic antibacterial effect. The complex preparation not only can effectively inhibit a plurality of gram-positive bacteria, but also can overcome the limitation that single streptococcal lyticase has weak activity on gram-negative bacteria, and significantly enhances the inhibiting effect on escherichia coli and salmonella. Especially, the complex preparation still has clear in-vitro antibacterial activity on multi-drug resistant escherichia coli such as ciprofloxacin and doxycycline, thereby providing a new way for developing a new type of drug for resisting drug-resistant bacteria.

This invention discloses a Bacillus amyloliquefaciens strain expressing bovine lactoferrin, its construction method, and its applications, belonging to the field of bioengineering technology. This invention utilizes the highly efficient protein secretion capacity of Bacillus amyloliquefaciens NFΔSE and the constitutive expression vector pMA5 for recombinant expression of bovine lactoferrin. Further, extracellular secretory expression of lactoferrin is achieved through signal peptide screening, and efficient fermentation synthesis of lactoferrin is realized in a fermenter through strategies such as optimized combined nutrient conditions and enhanced iron supply. Compared to traditional extraction processes, this process can produce lactoferrin through fermentation using this recombinant strain, effectively improving lactoferrin production capacity and demonstrating good industrialization potential.

The present application relates to the Pichia pastoris fermentation medium and fermentation method for expressing recombinant bovine lactoferrin, and belongs to the technical field of biochemistry, which solves the technical problem of improving the expression amount of bovine lactoferrin in the process of industrialized and large-scale preparation of recombinant bovine lactoferrin. The components and their proportions in the Pichia pastoris fermentation medium aqueous solution for expressing recombinant bovine lactoferrin are as follows: yeast extract 10-30 g / L, phosphoric acid aqueous solution 25-35 g / L, calcium sulfate 1.0-3.0 g / L, potassium sulfate 18-22 g / L, potassium hydroxide 4.0-5.0 g / L, glycerol 30-50 g / L, magnesium sulfate heptahydrate 7-13 g / L, ammonium chloride 4-5 g / L, PTM1 trace element solution 4-6 ml / L, and defoaming agent 1-2 ml / L. The high-density fermentation method of the present application is realized by controlling the technical parameters such as the dissolved oxygen amount, pH value, temperature and feeding medium rate in the fermentation process, so that the expression amount of bovine lactoferrin is improved to 4-5 g / L.

The application discloses a recombinant Pichia pastoris genetic engineering bacterium with high yield of lactoferrin, and simultaneously satisfies the following three modifications: overexpression of a bovine lactoferrin expression gene, mutation of an alpha mating factor signal peptide at position E86 to F, and overexpression of a PDI molecular chaperone gene. The application also discloses a construction method of the recombinant Pichia pastoris genetic engineering bacterium, and application of the recombinant Pichia pastoris genetic engineering bacterium in production of bovine lactoferrin. The 5L fermenter test result of the bacterium strain shows that the yield of exogenous protein is significantly improved, and is increased from 10.04 mg / L in a flask fermentation to 95.78 mg / L, nearly 10 times. The application is based on the Pichia pastoris system and is not related to complex culture condition change, and is low in cost and easy to enlarge. The method is not only suitable for production of bovine lactoferrin, but also provides a new modification idea for high-efficiency expression of other heterologous proteins in the yeast system.