2results about How to "Shorten fermentation time" patented technology

The present application belongs to the technical field of instant meat product processing, and discloses an instant ham and a preparation method. The method comprises low-salt pickling and semi-mature fermentation, high-temperature three-gradient fermentation after slicing and addition of probiotics, and the combination of vacuum temperature-changing fermentation ripening and bacteriostatic process, and processes the instant ham which is quickly fermented and matured, reduces the content of salt, inhibits the growth of rancidity and harmful bacteria, and is convenient to eat after opening the bag. The present application first proposes that the meat product after rapid fermentation is vacuum packaged and then subjected to special vacuum high-temperature fermentation ripening and bacteriostatic treatment at a high temperature of 49-52 DEG C. The process can not only significantly shorten the fermentation time to about 110-120 minutes, but also basically kill the non-sporulated vegetative microorganism cells in the vacuum-packaged ham, while allowing the probiotics to be retained to a certain extent and avoiding the pollution of microorganisms and other harmful substances thereafter. The "fast, low-salt, flavor, instant" ham product prepared by the present application technology cannot be realized by the existing ham fermentation technology.

The application provides a pertussis antigen recombinant expression vector and engineering bacteria and application thereof. The pertussis antigen recombinant expression vector comprises a resistance screening gene, an upstream recombinant nucleic acid fragment of a pertussis exotoxin gene and a downstream recombinant nucleic acid fragment, wherein the upstream and downstream recombinant nucleic acid fragments can respectively perform homologous recombination with the upstream and downstream of the pertussis exotoxin gene. The application takes the pertussis bacillus as a host, constructs an engineering bacteria ΔPT strain for producing FHA and PRN by knocking out the PT gene, simplifies the production process of the FHA and PRN antigens, maintains the high purity and immunogenicity of the FHA and PRN antigens, eliminates the interference of the PT protein in the production of the FHA and PRN antigens, avoids the PT protein detoxification process, and eliminates the risk of possible PT protein toxicity reversal.