Methods and Compositions for Limiting Viability of a Modified Host Cell Outside of Designated Process Conditions

Abstract

The invention provides methods and compositions for inhibiting proliferation of a modified host cell outside of a designated process condition. Compositions and methods for providing a host cell having reduced viability when exposed to natural conditions external to a controlled environment are disclosed.

What is claimed is: 
     
         1 . A cell genetically modified to have altered viability outside of a preselected non-nutrient ambient process condition. 
     
     
         2 . The cell of  claim 1 , wherein said genetically modified cell has a reduced expression of an engineered nucleic acid. 
     
     
         3 . The cell of  claim 2 , wherein said nucleic acid is endogenous. 
     
     
         4 . The cell of  claim 2 , wherein said endogenous nucleic acid has been excised from the genome of said cell. 
     
     
         5 . The cell of  claim 2 , wherein said engineered nucleic acid is selected from the group consisting of: a DNA repair pathway nucleic acid, a desiccation tolerance nucleic acid, a carbon concentrating mechanism nucleic acid, an engineered thermotolerance nucleic acid, an engineered pH tolerance nucleic acid, and an engineered flue gas dependence nucleic acid. 
     
     
         6 . The cell of  claim 1 , wherein said cell has been genetically modified to reduce expression of a gene, wherein the reduction of the expression of said gene decreases the viability of said cell outside of said preselected process condition. 
     
     
         7 . The cell of  claim 1 , wherein said genetic modification comprises a gene insertion. 
     
     
         8 . The cell of  claim 7 , wherein said gene insertion is introduced via site-specific integration. 
     
     
         9 . The cell of  claim 8 , wherein said site-specific integration is performed by a bacteriophage. 
     
     
         10 . The cell of  claim 8 , wherein said site-specific integration proceeds via the activity of an Int protein. 
     
     
         11 . The cell of  claim 1 , wherein said genetic modification comprises a gene knock out. 
     
     
         12 . The cell of  claim 1 , wherein said genetic modification reduces expression of a gene that encodes an enzyme that acts on a nucleic acid substrate. 
     
     
         13 . The cell of  claim 12 , wherein said enzyme repairs ultraviolet radiation-induced damage. 
     
     
         14 . The cell of  claim 12 , wherein said gene is selected from Table 1. 
     
     
         15 . The cell of  claim 12 , wherein said gene is selected from a group of  Synechococcus elongatus  genes consisting of: phr, phrA, uvrA, uvrB, uvrC, perA, mutM, mutY, radA, recG, mfd, and radC. 
     
     
         16 . The cell of  claim 12 , wherein the activity of said enzyme is selected from the group consisting of: deoxyribopyrimidine photolyase, DNA photolyase, excinuclease, DNA-dependent ATPase, helicase, formamidopyrimidine-DNA glycosylase, A/G-specific adenine glycosylase, DNA recombination, ATP-dependent DNA helicase, transcription repair coupling, and DNA repair. 
     
     
         17 . The cell of  claim 1 , wherein said genetic modification reduces expression of a gene that encodes an enzyme that is part of a carbon concentrating mechanism. 
     
     
         18 . The cell of  claim 1 , wherein said cell is a photoautotroph or a cyanobacterium. 
     
     
         19 . A cell comprising a genetic modification of a gene selected from Table 1, wherein said genetic modification reduces expression of said gene and reduces viability of said cell outside of a preselected amount of ultraviolet radiation. 
     
     
         20 . An engineered cell, said cell comprising: at least one engineered nucleic acid selected from the group consisting of: a DNA repair pathway nucleic acid; a pH tolerance nucleic acid; a flue gas dependence nucleic acid; a salt tolerance nucleic acid; and a carbon-concentrating mechanism pathway nucleic acid; wherein said engineered cell downregulates an endogenous protein as a result of of said engineered nucleic acid, or has a gene knocked-out as a result of said engineered nucleic acid.