A Novel and Simple Fermentation Approach for Adjusting the Amino Acid Composition in Plant Biomasses to Enhance Nutritional Value for Humans and Animals

Abstract

Humans and animals are unable to biosynthesize the so-called essential amino acids, which plants and their crops often lack in sufficient quantities. To address this challenge, we devised a simple two-stage fermentation strategy involving two safe microorganisms. First, Bacillus subtilis subsp. Natto was used to degrade resilient plant proteins into peptides and amino acids, which were metabolized, releasing ammonia. In the second stage, ammonia was utilized by an optimized Corynebacterium glutamicumnstrain to produce l-lysine. Starting with fava beans and rapeseed press cake, 37.5 g/kg and 29 g/kg of l-lysine could be generated, respectively. The concept developed could have great implications for the food and feed sector; by using safe food microorganisms, we have demonstrated that it is possible to alter the amino acid composition in plant biomasses, not only for the purpose of increasing the nutrient value, but also to reduce pollution caused by an excessive intake of protein.