Design and Testing of a Bacteriological Timer Device Herman Armstrong Morgan Schiermeier Rachel Klapper Jackie Schneider
The Device We have decided to create a biological timer. This idea was spurred by observing some of the previously created projects, which included biological clocks. Building on this idea, we want to very precisely monitor the time between when an organism begins to feed upon until it finishes feeding on a food source – in this case, a sugar.
The Repressilator Nature.com Periodically induces the synthesis of green fluorescence protein (GFP).
Arabinose C Promoter (araC) Tetracycline Repressor +LVA (TetR)
Assembly Using enzymes, araC can be cut out of its plasmid, and the plasmid containing tetR can be opened. araC can be inserted into the tetR plasmid through ligation.
E coli cell timer GFP reporter Overall project Step 2 Put timer device and reporter in bacteria
AraC TetR GFP Reporter Negative Regulation Arabinose Sugar No more sugar TetR No GFP (repressed) No TetR GFP (fluorescence activated) INPUT OUTPUT
Step 3 Test timer conditions and visualize results Overall project Glowing E. coli from Elowitz and Leibler
Conclusions Our goal was to build a new timer device to add to the parts registry Obstacles –Gel extraction of fragments – spin column –Ligation efficiency Next step –Alternative gel extraction methods –Sacrifice to cloning gods
Constructing a Biological Breathalyzer Cory Cheatham Brian Pink
The Device The Bio-Breathalyzer is a device designed to determine the blood alcohol concentration of an individual. It is constructed using DNA from Pichia pastoris, a strain of yeast with a diauxic metabolic pathway for ethanol and methanol. The alcohol sensor will utilize this metabolic activity, along with a fluorescent protein indicator fused with the alcohol oxidase gene (AOXI) promoter. When the ethanol is consumed, the E.coli transformed with this tagged gene will fluoresce. The amount of alcohol present will be based on the time it takes the bacteria to fluoresce.
Background Complex pathway for metabolizing methanol in spp. of the Pichia taxa Alcohol oxidase (AOX) serves as the major enzyme AOX encoded in AOX1 and AOX2 genes AOX converts methanol to formaldehyde
Pathway for ethanol metabolism also exists Ethanol is preferred If both ethanol and methanol are present, ethanol will be consumed first AOX gene will not be expressed until ethanol has been consumed Background
Growth and Carbon utilization of P. pastoris Methanol Ethanol
Construction Isolation of AOXI promoter Amplified AOXI promoter using PCR Flanked AOXI promoter with appropriate restriction sites using primers EcoRI AOXI promoter XbaI SpeI PstI EcoRI AOXI promoter XbaI SpeI PstI EcoRI AOXI promoter XbaI SpeI PstI AOXI promoter PCR
Construction Isolation of AOXI promoter Cloned PCR product into pCR2.1 vector + Transformation EcoRI AOXI promoter XbaI SpeI PstI EcoRI XbaI SpeI PstI AOXI promoter
Construction Isolation of AOXI promoter Transformed pCR2.1 vector with promoter into competent cells
Construction Checking AOX1 promoter clones Isolated AOXI promoter from pCR2.1 plasmid using EcoRI AOXI promoter AOXI promoter EcoRI +
Preparation of BBa_J61002 vector Obtained BBa_J61002 vector from registry Transformed BBa_J61002 into E. coli cells to amplify promoter RFP E. coli + Transformation Amplification Construction
Preparation of BBa_J61002 vector Extracted amplified BBa_J61002 vectors Extraction Construction
Ligation of AOXI promoter and BBa_J61002 vector Digested AOXI promoter clone and BBa_J61002 vector with XbaI and SpeI promoter RFP EcoRI XbaI SpeI PstI AOXI + XbaI SpeI AOXI RFP promoter + Construction
Ligation of AOXI promoter and BBa_J61002 vector Performed overnight ligation at 16 ºC Transformed ligation into E. coli cells AOXI promoter XbaI SpeI RFP + Ligation AOXI RFP Transformation AOXI RFP Construction
Culture transformed yeast cells Test response of yeast cells to ethanol Design device Method
Restriction enzyme cutting sites within AOX1 gene Introducing methanol and ethanol simultaneously in breathalyzer Obstacles