Microorganisms engineered to use unconventional sources of nitrogen

Abstract

Disclosed are genetically engineered organisms, such as yeast and bacteria, that have the ability to metabolize atypical nitrogen sources, such as melamine and cyanamide. Fermentation methods using the genetically engineered organisms are also described. The methods of the invention are robust processes for the industrial bioproduction of a variety of compounds, including commodities, fine chemicals, and pharmaceuticals.

1 - 27 . (canceled) 
     
     
         28 . A fermentation method of culturing a cell comprising:
 providing a cell comprising a non-native nucleic acid molecule encoding a cyanamide hydratase enzyme;   contacting the cell with a substrate, wherein the substrate comprises a nitrogen-containing fraction and a non-nitrogen-containing fraction;   the nitrogen-containing fraction comprises, in an amount from about 10% by weight to about 100% by weight, cyanamide, or a salt thereof; and   culturing the cell, wherein the cell can, unlike a cell of the same species that lacks the nucleic acid molecule, metabolize the cyanamide.   
     
     
         29 . The method of  claim 28 , wherein the substrate does not comprise an antibiotic. 
     
     
         30 . The method  claim 28 , wherein the substrate does not comprise ammonium or urea. 
     
     
         31 . The method of  claim 28 , wherein the substrate comprises lignocellulosic material, glucose, xylose, sucrose, acetic acid, formic acid, lactic acid, butyric acid, a free fatty acid, dextrose, glycerol, fructose, lactose, galactose, mannose, rhamnose, or arabinose, or a combination thereof. 
     
     
         32 . The method of  claim 28 , wherein the genetically engineered organism is contacted with the substrate in a fermentor. 
     
     
         33 . The method of  claim 28 , wherein the non-native nucleic acid molecule comprises any one of SEQ ID NOs: 15 and 22-37 or functional variants thereof.