Adaptive Laboratory Evolution of a Microbial Consortium Enhancing Non-Protein Nitrogen Assimilation for Feed Protein...

Area of Science:

• Agricultural Science
• Microbiology
• Biotechnology

Background:

• Growing global protein demand necessitates sustainable animal feed alternatives.
• Soybean-based feed impacts human food security, driving innovation in the feed industry.
• Utilizing agricultural waste like wheat straw for protein production is crucial for sustainable operations.

Purpose of the Study:

• To develop a microbial fermentation process for producing high-protein animal feed from wheat straw and non-protein nitrogen (NPN).
• To enhance microbial tolerance to NPN through adaptive laboratory evolution.
• To optimize solid-state fermentation (SSF) conditions for maximizing protein content in wheat straw.

Main Methods:

• Adaptive laboratory evolution of a microbial consortium using NPN and wheat straw.
• Solid-state fermentation (SSF) of wheat straw with an evolved microbial consortium.
• Optimization of SSF parameters including substrate type, inoculation, nitrogen addition, moisture, temperature, and duration.
• Scale-up of the optimized SSF process.

Main Results:

• Evolved microbial consortium showed a fivefold increase in NPN tolerance (up to 5 g/L), with optimal growth on ammonium sulfate.
• Optimized SSF conditions increased true protein content in wheat straw from 2.74% to 10.42%.
• The scaled-up SSF process (2.5 kg) successfully produced feed protein with 9.84% true protein content.

Conclusions:

• Microbial fermentation of wheat straw and NPN offers a sustainable method for producing animal feed protein.
• Adaptive laboratory evolution is effective in enhancing microbial tolerance to NPN for fermentation.
• This approach addresses protein shortages in animal feed and adds value to agricultural waste.