AbstractsBiology & Animal Science

Biomaterials in nature provide abundant source of inspiration for the design and synthesis of novel high-performance materials. Nacre, a bio-mineralized material found in the inner lining of seashells has recently gained attraction due to its impressive material properties and eco-friendly nature. This ultra-tough coating could become inexpensive and can be the next-generation technology in aerospace and civil engineering if produced synthetically. The biological production of nacre can make building bio-concrete on Moon and several architectural applications possible. Controllability in the production of such biomaterials using photo-induction of different wavelengths of light, still remains a challenge. Light is an ideal tool to control living cells since it induces output through an external stimulus1. This provides great flexibility in controlling cells without having to manipulate the cell at genetic and metabolic level1. Light-mediated control of gene expression has various applications in the field of functional genomics, systems biology and biotechnology1. Previously a recombinant red light-sensor in Escherichia coli was engineered by Tabor et.al (2005) by combining Cph1, a red/far-red light switchable cyanobacterial phytochrome and EnvZ/OmpR two-component signalling pathway natively present in E. coli. Thereafter, they reported the development of a green sensor in E. coli from CcaS-CcaR, a green/red photoswitchable two-component system found in cyanobacteria Synechocystis2. This project will study the expression of both red and green sensors in E. coli to construct spatial patterning of layers of output, with further purpose of producing bio-layers of nacre. Study of the two- optical control of transcription across a layer of engineered cells will be the prime aim. Creation of patterns using these engineered cells can be helpful in designing the production of alternate output layers. The transfer function (the relationship between input strength and output strength) of each sensor individually and in combination will be studied, as well as tuning the output through different durations of light application. Fine tuning of the circuit to improve the background output is of high consideration for such a light-switch based application. Therefore, an attempt to create a random RBS library in order to reduce the background output signal given by the sensors under dark will be carried out.