BerkiGEM2007Present2
From 2007.igem.org
A Freeze-Drying Device
Bactoblood needs the ability to be stored for long periods in a freeze-dried form so that it can be stockpiled and easily transported. We therefore sought a genetic device that could improve the Bactoblood's structural integrity during dessication. We designed two distinct desiccation devices: one that utilizes the disaccharide trehalose and one that involves the small molecule hydroxyectoine.
Trehalose
Trehalose is pulled right out of the E.coli genome and consists of the genes otsA and otsB. Naturally otsB comes first because the production of that is more important that otsA so in my operon otsB comes before otsA. Together the sugar Trehalose is produced which helps the cell recover from freeze-drying. OtsB encodes for a 29.1-kDa trehalose-6-phosphate phosphatase and otsA encodes for a 53.6-kDa trehalose-6-phosphate synthase. Together they make up a trehalose-6-phosphate synthase/phosphatase complex. Naturally, the 3' end of the otsB coding region overlaps the 5' end of the otsA coding region by 23 nucleotides. The Trehalose helps the frozen dehydrated cells to recover back to a functioning hydrated state. Not all cells survive the freeze drying process but Trehalose increases the rate of success. Trehalose structure:
Hydroxyectoine
Streptomyces Chyrsomallus consists of many genes; however, I was only interested in 4 genes and they are thpA, thpB, thpC and thpD. These 4 genes will help initiate the production of hydroxyectioine. The 4 genes should be arranged in this order: thpA-rbs-thpB-rbs-thpC-rbs-thpD. thpD is the gene that plays a crucial role in the production of hydroxyectoine. The other three genes are there to initiate the process. When inserted into a bacterium, hydroxyectoine will prevent dessication and many other extremes. It will protect the bacteria's proteins and cell membrane.
