Difference between revisions of "Part:BBa K398108"

Revision as of 18:44, 27 October 2010

Salt tolerance cluster

Introduction

Salts are essential for life, but not all life requires the same amount or the same type of salts. But because of these varying conditions the salt stress differs from environment to environment. It is difficult for a species to adapt to different salt stress levels. To compensate for the cells innate vulnerability to higher salt concentrations we chose a protein from Chlamydomonas sp. W80 that increases the salt tolerance of E.coli. This protein is called bbc1.The exact mechanism of the increased salt tolerance is as of yet unknown. But since bbc1 shows a high homology to RBS binding proteins, it is theorized that it may prevent/stabilize the folding structure of the ribosome under high salt stress conditions.

Characterization

The salt tolerance induces by this BioBrick was tested by using NaCl in LB and M9 (containing 40 mM casaminoacids) media from 0 to 1M salt concentrations, it was compared to another of the TU Delft 2010 BioBricks which had the same antibiotic resistance, and same expression level (but of another protein which did not cause increased salt tolerance).

The [http://2010.igem.org/Team:TU_Delft#page=Project/tolerance characterization of BBa_K398108] has been described on the TU Delft iGEM Team 2010 wiki.

Results

At 0.2 M some effects of the increased salt stress starts to appear, at this concentration the strain containing the BioBrick showed a significant increase in growth rate in comparison to the negative control (BBa_K398027). At higher salt concentrations the salt stress causes a multitude of effects and the BioBrick probably does is not able to counter all these effects. Thus, at the higher salt concentration the strain also shows effects of higher salt stress. In conclusion one can see that the BioBrick indeed increases the salt tolerance of the cells at concentrations higher then 0.3 M Sodium Chloride. The general increase in tolerance varies between 10% and 35% depending on the Sodium Chloride concentration.

References

1. S. Tanaka,K. Ikeda, H. Miyasaka, Enhanced Tolerance Against Salt-Stress and Freezing-Stress of Escherichia coli Cells Expressing Algal bbc1 Gene. Current Microbiology, 42:173-177 (2001)
2. Y. Suda,T. Yoshikawa,Y. Okuda,M. Tsunemoto,S. Tanaka,K. Ikeda,H. Miyasaka,M. Watanabe,K. Sasaki,K. Harada,T. Bamba,K. Hirata, Isolation and characterization of a novel antistress gene from Chlamydomonas sp. W80. Journal of Bioscience and Bioengineering, 107(4) 352-354 (2009)
3. Y. Hase, S. Yokoyama, A. Muto, et al. , Removal of a ribosome small subunit-dependent GTPase confers salt resistance on Escherichia coli cells. RNA Society, 15:1766-1774 (2009)

Sequence and Features