Waiting for Loading...
Considering that our protection object is marine metal transportation pipeline, NEU_China 2023 team plans to build an engineering bacterium with Escherichia coli MG1655 as chassis bacteria and apply it to marine metal anticorrosion.
The product proposed by our project is a bacterial coating, which means that our engineering bacteria and related substances will be coated on the metal surface in marine environment for the best protection effect. We will also use the mineralization of biofilm to prolong the service life of anticorrosive coatings and improve the biological safety of metal corrosion protection technology based on biofilm.
Through communication with the company and professionals, we have worked out a practical implementation plan for this project, and hope to provide practical, effective and environmentally friendly help for marine metal anticorrosion.
The metal surface coating solution designed and manufactured by us contains modified Escherichia coli which can produce biofilm. After secreting CsgA-Spytag, it connects with another component Mfp-spycatcher in vitro to form a highly adhesive biofilm. In our design, the use of the anticorrosive coating material is divided into two steps:
(1)Coating on metal surface to form biofilm.
(2)The biofilm in seawater completes natural biomineralization.
Our end users are companies, harbors and professionals involved in marine metalwork related to the protection of metalwork in the marine environment. Generally speaking, our end users include all people related to marine metal products.
In our project, the product is applied to the metal surface to prevent corrosion, and is mainly used for static corrosion, such as small metal parts of hull, metal pipes, metal guardrails of wharf and steel pipe columns of port.
Escherichia coli MG1655 is a common and widely distributed strain, which does not cause common diseases and infections, and does not corrode itself and its products, and does not aggravate metal corrosion.
According to our project design, bacteria form a stable biofilm on the metal surface and then induce biomineralization. In addition, for the sake of biosafety, we added a suicide switch to the engineered bacteria, and integrated a toxic protein ccdB gene regulated by arabinose-induced promoter into the bacterial genome, so that bacterial suicide death can be realized after adding arabinose when necessary.
Escherichia coli MG1655 belongs to Class 2 biosafety level (BSL-2), which can reduce the safety risks of laboratory personnel and environment to a certain extent.
Traditional corrosion protection methods include coating, surface treatment, corrosion resistant materials,corrosion inhibitors, electrochemical protection and so on. However, these technologies still face many inherent defects and deficiencies.
| Corrosion protection | Disadvantages |
|---|---|
| Coating | Environmental pollution is large, heavy metals exceed the standard, and construction technical requirements are high |
| Corrosion inhibitors | Some chemicals in corrosion inhibitors have potential safety hazards, for example, chromate has carcinogenic effect on human beings and is easy to degrade, which seriously threatens human health and ecological environment |
| Cathodic protection | Expensive and unstable |
Our product contains genetically modified bacteria，which may have hidden dangers such as horizontal gene transfer, affecting ecological balance or evolving to produce abnormal functions after entering the environment. Although they have no resistance to broad-spectrum antibiotic, However, for the sake of safety, we integrate a toxic protein ccdB gene regulated by arabinose-induced promoter into the bacterial genome, so that bacterial suicide death can be realized by adding arabinose when necessary. If our bacterial agents are produced and utilized anywhere outside the laboratory, extensive tests need to be carried out to ensure the effectiveness of the suicide genetic circuit and absolute safety to the environment and human beings.
Firstly, considering that bacteria may produce secondary metabolites that may aggravate metal corrosion during their growth, we still need to conduct extensive simulation experiments in the laboratory to ensure that their impact on cultural relics is within a low and controllable range.
Secondly, in order to get the final commercial product, we need to conduct further market research and improve the formula of the kits to minimize costs and ensure the effectiveness.
Finally, we must give extremely clear guidance on how and where to use our product and conduct relevant risk assessment to prevent any biosafety problems caused by vague instructions.