Lignocellulose Decomposer

What’s next?

We have successfully constructed and submitted several BioBricks with the function of cellulose or xylan degradation. However, to complete our project and achieve our original goal, there are still several tasks to be done.
1.We have tried to use enzyme assay methods to determine the activities of secretory enzymes lignin peroxidase, Mn peroxidase, and glyoxal oxidase, however with unsatisfying results. The cause for this phenomenon might vary from low protein expression levels to unsuitable fermentation condition (temperature, pH, etc.). We will continue to explore the optimum condition for yeast fermentation and realize the function of these enzymes.
2.We have designed to codisplay cellulose degradation enzymes (endoglucanase and β-glucosidase) on the same yeast cell surface and xylan degradation enzymes (endoxylanase and β-xylosidase) on the same yeast cell surface. However, so far we have only been able to construct single display systems, and it has been verified by immunofluorescence labeling. In the future we will realize the codisplay system by second electroporation.
3.After the lignin-degradative enzyme secretory system is improved and the cellulase codisplay system and xylanase codisplay system are constructed, we will co-cultivate the engineered yeasts as planned to enhance the efficiency of ethanol production to be even sufficient for factory production.

Second generation bio-ethanol

Using cheap lignocelluloses to produce bio-ethanol is one of the major ways to solve the energy crisis. However, the low degradation efficiency of this technique is a main factor that hinders its popularization. Many scientists are seeking for enzymes with higher efficiency, but we are taking another route to achieve this goal by increasing the concentration of enzymes by displaying the enzymes on the surface of Pichia pastoris. Furthermore, yeast can use glucose to ferment ethanol directly. In the future, there might be a second generation of bio-ethanol production technique based on this idea to provide new methods for renewable energy production.

Application of standardized secretory vector

In future, we can use this kind of vector for mass production of functional enzymes or medical proteins, such as recombining common enzymes with these vectors to produce industrial enzymes for food, dyeing, paper making and daily chemicals, or to recombine insulin gene with the vector to produce insulin in large scale, providing low-cost medicine for patients.

Microbial Fuel Cell

Bioelectrogenesis

Traditional bioelectrogensis … but our circuit is well designed and of good quality. Although setbacks in assembly prevented us from actually testing the complete circuit, we utilize ordinary differential equations to generate a comprehensive and scientific model describing the diffusion of proton, the regulation of genes and the cell growth curve. We have successfully proved the feasibility of the project both in micro and macro. With its strengthened efficiency and robustness, this project can be applied not only to bioelectrogensis, but also to the design of biocell.

Disposition of polluted-water

One of the materials used in this project is the polluted acid or alkali water. Therefore, we can achieve polluted water treatment in this circuit by regulating the pathway of anaerobic respiration to generate electron which will react with proton. We can enhance the efficiency of disposing polluted water and get higher-efficiency engineering bacterium by redesigning some pathways of heavy metal absorption and organism degradation in E.coli.
In future application, this project can be applied to acid or alkali polluted-water treatment and electricity generation.

Utilization of biofilm

As we know, a lot of projects have been done to eliminate the effect of biofilm. However, in this project, we assume that we can construct anaerobic environment by means of biofilm and get anaerobic fermentation environment which can be utilized to activate certain path in the engineering bacteria, sequentially activate relevant function of the engineering bacteria and make better use of the biofilm.