Team:NAU-CHINA

DI - DEFICENCY HEALTHY TOXIC

Selenium has one of the narrowest ranges between dietary deficiency (<40 mg/day) and toxic levels (>400 mg /day) , leading to the unbalanced distribution of selenium in space.

To solve this problem, NAU-CHINA 2021 focuses on the selenium reduction and recycling through engineered bacteria to form selenium nano-particles (SeNPs), which is of eminent qualities in many fields.

Fertilizer Fertilizer
ssuE sefA SeO 4 2- SeO 3 2- Se 0 SeNP

In this project, we selected Escherichia coli BL21(DE3) as our chasis and mainly designed a genetic circuit containing two major modules, ssuE & sefA to achieve our goal.

Several convictive evidences has shown that we had accomplished our experiment and produced some prototype SeNPs fertilizer in lab-scale eventually. The subsequent pilot-scale and even industrial implementation are on the horizon.

Gene Circuit Stochastic model is built to find best promoter combinations and to calculate theoretical yield in laboratory environment, using tau-leaping algorithm. Then we add deterministic model when it comes to natural environment.

SeO 3 2- SeNPs
Selenite Concentration Temperature pH 12mM 16°C 6 15mM 30°C 7 18mM 37°C 8 14.33mM 30.26°C 6.75

Response Surface Method is used to provide a theoretical basis for the best conditions for large-scale production of SeNPs.