The present invention provides for a mechanism to reduce glycerol production and increase nitrogen utilization and ethanol production of recombinant microorganisms. One aspect of this invention relates to strains of S. cerevisiae with reduced glycerol productivity that get a kinetic benefit from higher nitrogen concentration without sacrificing ethanol yield. A second aspect of the invention relates tometabolic modifications resulting in altered transport and/or intracellular metabolism of nitrogen sources present in corn mash.

Disclosed herein are methods of increasing nitrogen fixation in a non-leguminous plant. The methods can comprise exposing the plant to a plurality of bacteria. Each member of the plurality comprises one or more genetic variations introduced into one or more genes or non-coding polynucleotides of the bacteria's nitrogen fixation or assimilation genetic regulatory network, such that the bacteria are capable of fixing atmospheric nitrogen in the presence of exogenous nitrogen. The bacteria are not intergeneric microorganisms. Additionally, the bacteria, in planta, produce 1% or more of the fixed nitrogen in the plant.

Disclosed herein are methods of manufacturing therapeutic proteins.

A method of quantifying ammonia, which method includes: performing a first reaction in which a test liquid containing ammonia is reacted with ATP and L-glutamic acid in the presence of glutamine synthetase to produce ADP; performing a second reaction in which the produced ADP is reacted with glucose in the presence of ADP-dependent hexokinase to produce glucose-6-phosphate; performing a third reaction in which the produced glucose-6-phosphate is reacted with an oxidized NAD compound in the presence of glucose-6-phosphate dehydrogenase to produce a reduced NAD compound; and quantifying the reduced NAD compound to quantify ammonia.

Methods and systems are provided for generating and utilizing a genetically engineered bacterium comprising a modification in glnD, wherein said modification is selected from the group consisting of: deletion of the entire gene, deletion of substantially the entire gene, deletion of an ACT domain, deletion of more than 50% of an ACT domain, deactivation of an ACT domain, and deactivation of an UTase domain.

The present disclosure is directed to genetically engineered bacteria strains with enhanced biofuel-producing capabilities from cellulosic substrates. The bacteria strains of the present disclosure comprise an inactivated Type I glutamine synthetase gene. The present disclosure is also directed to methods of producing biofuels from cellulosic biomass using the genetically engineered bacteria strains.

A method of quantifying ammonia, the method includes performing a first reaction in which a test liquid containing ammonia is reacted with adenosine triphosphate and L-glutamic acid in the presence of glutamine synthetase to produce phosphoric acid, performing a second reaction in which the produced phosphoric acid is reacted with pyruvic acid in the presence of pyruvate oxidase, and measuring a component consumed or produced by the second reaction, to quantify ammonia, wherein a reaction to produce adenosine triphosphate from adenosine diphosphate mediated by pyruvate kinase is not carried out.

The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

Disclosed is an expression vector comprising a polynucleotide encoding for a glutamine synthetase with reduced activity compared to a wild type glutamine synthetase. Also disclosed are host cells, methods for preparing stable cell line, methods of producing polypeptide of interest, and kits thereof.

Biosensor systems for detecting levels of nitrogen-containing molecules are provided. Further provided are biosensor system components and various detection platforms, methods, and kits.