Lactoferrin was first identified from milk in 1939, and was first
extracted from the milk in 1960. After that, it was proved to exist in all
kinds of animal and human body (especially milk), and was proved to be an
effective antimicrobial protein against all kinds of pathogens.
Lactoferrin in milk is now considered as a protection against different
diseases, since cattle have a weak immune system.
The special characteristics of Lactoferrin provide different medical and nutritional value. LF can eliminate pathogens in an effective way as a natural antimicrobial protein. It also has an iron transferring function in blood and is used in curing iron-deficiency anemia and other diseases related to the scarcity of iron by simply ingesting certain amount of LF. Recently, it was also proved to be effective in anti-inflammatory, anti-cancer and anti-parasite treatment.
LF plays an important role in all kinds of domain, but due to the complexity and fussiness of extracting, the relatively scarcity of ingredients and the low production rate, the price of LF is relatively high. In recent years, scientists are trying to use microorganisms to produce LF using gene editing technology. Escherichia coli (E. coli), a basic biomaterial, is often the first choice of protein expression due to its simple technical and cultural operation, and relatively low price, also, avoiding potential ethical issue. For another reason, the use of E. coli in producing different domains are highly mature and are ready for commercial and academic use. For example, insulin, a kind of protein which are used in curing diabetes, is mostly produced by using edited E. coli.
Our proposition aimed to use E. coli to produce LF. However, the process could not be executed as we expected since LF, as an antimicrobial protein, may eliminate the bacteria during the procedure. During our research, we found out that iron cations can prevent E. coli from being killed by LF, making the procedure smoothly and effectively. The mechanism is that LF can remove most of the Fe cations which are necessary to E. coli, and proceeding the system with exceed Fe cations can provide necessities. Therefore, we planned to introduce Fe2+ and Fe3+ into the system, trying to stimulate and motivate the process.
We hypothesized that the iron cations could keep E. coil survive for a relatively longer time, and therefore be able to produce a larger amount of LF. These products could be used in curing diseases and saving lives.