BIOLOGY

Improvement

Compared to last year’s project, the project this year brings in a new amplifying system in signal amplifying for microbe, which significantly improves the efficiency of signal amplifying. For the feature of project, we build a cascade amplifier in microbe by imitating cascade amplifier in circuitry, based on amplifying system of last year.

Last year: In the plasmid of amplification system, two activating transcription factors are in constant expression and remain in a certain concentration. With a certain level of autoinducer PAO1, PAO1 integrates with lasR, the complex of which are bond to the target site of las promoter, then activating it and control the expression of the downstream reporter gene GFP in accord with the concentration of the amount of combination.

This year: Inside the upriver bacteria, certain enzyme will digest the oligopeptides that is from glycopeptide so that the arabinose will be released and induce the engineering bacteria expressing LasI protein. The protein can catalyze matrix producing a large number of small molecules PAI1. When PAI1 free diffuse into the downstream bacteria, it will combine with the constitutive expressed LasR protein and form a transcription factor complex. The combination between complex and the pLas promoter accelerate the process of transcription and translation to generate the Rhl1 enzyme, which can catalyze producing the autoinducer PAI2 from system RhIIR. The complex of PAI2 and RhIR protein that is mediated-expressed by double promoter in bacteria can act on pRhl promoter and induce the engineering bacteria to express GFP.

Innovation

We use aptamers as intermedia innovatively, which forms a competitive inhibition system, so as to realize the goal this year that detecting biochemical macromolecules by microbe.

This year: Outside bacteria, we combine the artificial oligopeptides with the aptamers. As the macromolecules get into the measurement system, they will take places of glycopeptide and leave them as dissociated molecules. Finally, these free glycopeptide will enter the transformed engineering bacteria.

HARDWARE

Improvement

For fluorescence detection device, the improvement are as following. First of all, we use blue laser pen instead of blue LED light, for its light concentrates better and the energy is more powerful, which remarkably improves the efficiency of fluorescent protein stimulation. Secondly, given that fluorescent chromaticity is single, we use sensor OPT101 instead of sensor TCS32XX to improve accuracy, which is sensitive to grayscale rather than chromaticity. Finally, we use UART screen instead of LED panel, which sharply improves the user interaction interface and is more interactive.

Innovation

In order to make microbe express fluorescent protein rapidly, we innovatively build a bacterial culture device, which refers to thermostatic shaker in laboratory. The details is shown in “Hardware-Design”.