To enhance the effects of decontamination in various fields, we use the Alkaline Cellulase as detergent additive. An Alkaline Cellulase was introduced into the Escherichia coli and controled by P43 promoter, thus the target enzyme can be highly produced with the help of Kil, which is one of the core elements of our project. What’s more, MdfA , a proton pump across the cell membrane, is added to transport the proton into the cytoplasma, and release Na+/K+ at the same time, resulting in cell survival in alkaline industry wastewaters as high as pH 10. Another highight of our project is that we also added a ccdAB suicide system to our e-machine, by this we could remove the biological machine whenever we need for biological safety.

The Kil element

The protein Kil can promote the secretion of periplasmic protein, with no limitation of the molecular weight of protein. When the Kil gene is expressed, bacteria can produce more proteins than that in periplasmic cavity, inducing the host bacterium to synthesis even more proteins. Besides, in E. coli natural plasmid contains the genes of colicin and related substance, which can increase the permeability of outer membrane. Thus the colicin can be moved to the outside to kill other bacteria.

The CcdB Suicide System

The CcdB system is a toxin-antitoxin system, which codes CcdB as a kind of toxin protein. CcdB can interfere with DNA synthesis to kill the host cell. The engineered E. coli is created for industrial using, so the suicide system needs to be controlled freely. The channel is closed by a repressor under normal conditions, with no CcdB produced. When adding IPTG, the repressor’s structure is changed and the channel would be opened. The CcdB forms and starts to kill the host cell.

In papermaking industry

Alkaline Cellulase is widely used in papermaking. One of the important fibrous materials is daily waste papers. Compared with chemical method, enzymatic process has many advantages, for example, the drainage properties of pulp is improved a lot, and the whiteness of paper is significantly improved.

In textile industry

Through enzymatic hydrolysis, cellulase can open nodules in cloth to make cloth more fluffy and comfortable. The surface can be made more smooth and colorful. Experience tells that alkaline cellulase is environment friendly, since it could reduce the sewage disposal and improve the washing efficiency.