Genetically modified diazotrophs and methods of using same
This disclosure describes a genetically-modified diazotrophic microbe and methods that involve the genetically-modified diazotrophic microbe. Generally, the diazotrophic microbe is modified to excrete a nitrogen-containing compound in an amount greater than a comparable control diazotrophic microbe. The genetically-modified diazotrophic microbe can be co-cultured with a non-diazotroph and increase the growth of the non-diazotroph.
1. A method of increasing growth of a non-diazotroph, the method comprising:
co-culturing the non-diazotroph; and
an Azotobacter spp. genetically modified to excrete a nitrogen-containing compound in an amount effective to support the growth of a non-diazotroph in co-culture, the genetic modification comprising:
a deletion or disruption of at least a portion of ureABC;
a deletion or disruption of at least a portion of amtB; or
a deletion or disruption of at least a portion of nifA2;
wherein the Azotobacter spp. is provided in an amount effective to increase the growth of the non-diazotroph compared to growth of the non-diazotroph in the absence of the diazotrophic microbe.
2. The method of claim 1 wherein increasing the growth of the non-diazotroph comprises increasing the growth rate of the non-diazotroph.
3. The method of claim 1 wherein increasing the growth of the non-diazotroph comprises increasing the cell density of the non-diazotroph.
4. The method of claim 1 wherein increasing the growth of the non-diazotroph comprises increasing the crop yield of the non-diazotroph.