Venus is shrouded by an opaque layer of highly reflective clouds of sulfuric acid and dense carbon dioxide. We should clone two sulfur reductase enzymes to turn SO2 into H2S .

Construct our new parts: sulfite reductase enzymes

Methods: Sulfite reductase stable expressing cyanobacteria cost longer time and a lot of money to set up. To check the function of constructed gene in advance, we perform a chemical nephelometry assay to detect H2S. The reaction fomula are as followed: Then, we cooperate with Chung Hwa Pulp Corporation and get some industrial waste water and gas. Finally culture our Cys I and Dsr expressing E.coli in waste water and gas for 24hr and 48 hr.

Results: Fig 4. H2S production of CysI and Dsr

Fig1. 1.DsrI-II (from desulfovibrio desulfuricans)

Fig2. CysI (from PAOI, pseudomonas aeruginosa)

Ecoli expressing CysI or Dsr could turn sulfite into H2S!!!!!

Fig3. Cooperate with Chung Hwa Pulp Corporation

Project Sulfur Oxide Terminator

Motivation :

1. Nowadays, environment on Earth is deteriorating. Living on the outer space deserves our implement.

2. Compared to Mercury & Mars, Venus is still a geologically active planet like the earth, which can provide the element that creatures need.

3. Combining the synthetic biology and the concept of endosymbiosis, we granted engineered cyanobacteria and eukaryotes the ability to colonize Venus and expand our territory.

Goals :

Problems in Venus conquer Solution through Synthetic biology

Sulfur dioxide is filled with Venus atmosphere.

Project “Sulfur Oxide Terminator” turned SO2 into H2S.

Our Venus platform, cyanobacteria, couldn’t live with H2S.

Project “Sulfide as Energy Generator” rendered cyanobacteria proceed sulfide-dependent photosynthesis.

There is no creature on Venus.

Symbiosis of engineered cyanobacteria and eukaryotes created the Venusians!!!

Abstract After solving the problem of SO2, we should create creatures which could use CO2 and H2S to produce their nutrient and energy. We hypothesized engineered Synechococcus SP. PCC 7942 could turn the Venus gas, sulfide dioxide(SO2), into H2S(hydrogen sulfide) and then use H2S to be their reducing energy and do the sulfide-dependent photosynthesis. Function assay was evaluated by E.coli.

Construct our new part: SQR(sulfide quinone reductase), from Synechococcus sp. PCC 7002 plasmid pAQ7

Methods: H2S consumption was evaluated by the same method described in Project Sulfur Oxide Terminator. Results: Fig 6. H2S consumption of SQR+/- ecoli after 24hrs(left) or 48hrs(right)

Project Sulfide as Energy Generator

Fig 5. SQR

E.coli expressing SQR could use H2S to be their reducing energy!!!

Invasin(inv) from Yersinia pestis and listeriolysin O(llo) from Listeria monocytogenes made bacteria invasion to cells. We hypothesized that by symbiosis, if engineered cyanobacteria could invade into eukaryotes and produce energy by photosynthesis, Venusians creating was not only a dream!

Methods: Coculture engineered Synechococcus sp. PCC 7942(inv and llo +, provided by Prof. Pamela A. Silver) with mammalian cells (J774 macrophage or induced pluripotent stem cells) for 24 hours and observe the invasion result.

Results: Fig 7.

J774 macrophage with cyanobacteria invasion

iPS cells with cyanobacteria invasion

Cyanobacteria transformed with inv-llo could invade into mammalian cells!!!

Project of Venusians Creating

Nitrogen oxides are one of the most notorious pollutants in the modern days. Meanwhile, during the processes of denitrification, sulfide compounds and nitrate acted as electron donor and acceptor respectively. We aimed to reduce nitrogen oxides and oxidize sulfide compounds, which is beneficial not only to our Venus Marvel project but also to environment on Earth.

Construct and Simulation: Modeling a simple simulation to

estimate the efficiency and productivity of nitrogen for our modified bacteria.

Project Denitrifying machine

Scan for team wiki

Results: Denitrifying machine was a good way to eliminate toxic NOx compounds!!!

Abstract: Cadmium contamination is a serious problem in many countries. To solve it, we’ve built the endosymbiotic system to clean up cadmium contamination. The endosymbiotic system between the soil-living amoeba Dictyostelium discoideum and engineered E.coli would be a great niche.

Design: 1. Into the cell: invasin and Listeriolysin O made engineered E.coli get into amoeba. 2. Cadmium accumulation: Genes smtA(BBa_K896010) and mnt(BBa_K896011) enhanced E.coli’s ability of gathering cadmium ions. 3. Kill switch of E.coli and amoeba: Genes zinTp(K896008), lacI, DdaifA and HlyA(BBa_K223054) were used to make sure our genetic modified organisms would stay in the area and wouldn’t become another pollution source to our environment.

Results:

Fig 8

Fig 9.(left) The transcription rate of zinTp is fairly low when there is no cadmium ion. ZinTp could be a good Cd(II) biosensor. (Right) E.coli expressing smtA had stronger resistance to cadmium toxicity.

Back to Earth-- Biosafety Cadmium Collector