Engineering strain for controlling adsorption and escape of heavy metals as well as construction method and application of engineering strain

Abstract

The invention discloses an engineering strain for controlling adsorption and escape of heavy metals as well as a construction method and an application of the engineering strain. The engineering strain is a bacterium obtained by introducing a complete system into a host bacterium; the complete system comprises a heavy metal ion regulation protein, a heavy metal ion adsorption protein displayed on the surface of an ice nucleation protein, a streptavidin binding protein displayed on the surface of the ice nucleation protein and an escape control element, and the escape control element comprises repressor proteins PhlF, TetR, LacI and a lethal protein. Based on a synthetic biological technology, the invention provides a water body heavy metal adsorption and escape control microorganism which integrates the functions of heavy metal adsorption, microorganism enrichment after adsorption, escape control and the like in escherichia coli or pseudomonas putida, and the construction of a complex, fine and predictable genetic loop is realized by utilizing a standardized biological element; after optimization design, gene lines of adsorption, enrichment and death behaviors can be completed under the condition of mercury ions with different concentrations.

Description

technical field [0001] The invention belongs to the technical field of genetic engineering, and in particular relates to a heavy metal adsorption and escape control engineering strain and its construction method and application. Background technique [0002] Hg, Cd, Pb, etc. in the natural environment will have adverse effects on the growth of organisms in nature, and will eventually threaten human health under the enrichment of the food chain. The direct discharge of industrial pollutants without strict treatment of heavy metal components has caused very serious pollution to some water bodies. Therefore, the cleanup of heavy metals in water bodies has become a major environmental problem that needs to be solved urgently. [0003] Some microorganisms in the natural environment participate in the biochemical cycle of heavy metals and become an important part of it. These natural microorganisms are an important link in maintaining the balance of mercury in the environment. U...

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Problems solved by technology

However, the adsorption efficiency of heavy metals based on microorganisms is not high, and further modification is needed to improve the activity; on the other hand, all the heavy metals that are adsorbed still exist in the environment, and there is a risk of secondary pollution. It is urgent to develop a fast , low-cost recycling means; finally, biosafety issues have increasingly become a hot topic in the international community. It is also a general trend to develop anti-escape technologies for genetically modified microorganisms and realize their environmental control. Existing escape control technologies are often still in the academic literature. At the theoretical level, there is little applied research

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