GlnD-Modified Bacteria for Nitrogen Fixation in Non-Legumes

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Solution Overview

Problem

Current methods struggle to efficiently enhance nitrogen fixation in non-leguminous crops, such as wheat, rice, and maize, especially in the presence of exogenous nitrogen sources like fertilizers.

Innovation Solution

A genetically engineered bacterium with modifications in genes like glnD, glnA, rpoN, NifA, NifL, NifH, and GlnE is used to increase nitrogen fixation in plants. These modifications alter the expression or activity of these genes, leading to increased nitrogenase activity and ammonium excretion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If genetically engineered bacteria are used to enhance nitrogen fixation, then nitrogen fixation efficiency is improved, but the complexity of the biological system increases

Engineering Contradiction:

Improvenitrogen fixation efficiencyVSAvoidbiological system complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The invention divides the nitrogen fixation system into separate functional components: the bacterial strain provides nitrogen fixation capability through modified glnD and nif genes, while the plant host provides the growth environment. This segmentation allows optimization of each component independently, improving overall nitrogen fixation efficiency without requiring complete system redesign.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The genetically engineered bacterium acts as an intermediary between atmospheric nitrogen and the plant. The bacterium fixes atmospheric N2 into ammonium, which then transfers to the plant. This intermediary approach enables nitrogen fixation in non-leguminous crops that normally lack this capability, improving productivity without directly modifying the plant's complex genetic system.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If nitrogen fixation is enhanced in the presence of exogenous nitrogen, then nitrogen availability to plants is improved, but the regulatory control of nitrogen fixation becomes more difficult

Engineering Contradiction:

Improvenitrogen availabilityVSAvoidregulatory control

Core Design Contradiction:

Quantity of substanceVSEase of operation

Solution Approach 1:

The invention changes the regulatory parameters of the bacterial strain by modifying the glnD gene, which normally responds to nitrogen availability. The modified glnD mutant maintains high nitrogen fixation activity even when exogenous nitrogen is present, as the modification alters the sensor or response mechanism. This allows nitrogen availability to be improved while bypassing the usual regulatory control difficulties.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If genetic modifications are made to increase nitrogenase activity, then nitrogen fixation rate is improved, but the stability of the bacterial strain may be compromised

Engineering Contradiction:

Improvenitrogen fixation rateVSAvoidbacterial strain stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The bacterial strain is pre-modified with stable genetic changes to the glnD and nif genes before application to plants. These preliminary genetic modifications ensure that the strain maintains high nitrogenase activity and stability throughout the plant growth cycle, rather than requiring continuous optimization during the process.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The genetically engineered bacterium effectively increases the amount of atmospheric nitrogen fixed in plants, even in the presence of fertilizers, thereby enhancing plant growth and reducing the need for chemical nitrogen inputs.

Implementation Method 1

In biological systems, an enzyme known as nitrogenase catalyzes the reaction which results in nitrogen fixation

Methodology Applied

Scientific EffectNitrogen fixation: Catalysis

Implementation Method 2

These modifications alter the expression or activity of these genes, leading to increased nitrogenase activity and ammonium excretion

Methodology Applied

Scientific EffectAmmonium excretion:

Data Source

PatentUS20250115529A1Gene targets for nitrogen fixation targeting for improving plant traits

Publication Date: 2025.04.10 PIVOT BIO INC

AI summary

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.