Evaluation of Tenebrio molitor protein hydrolysates as biostimulants improving plants growth and root architecture

The growing demand for agricultural products has led to increased research on biostimulants. In particular, amino acid-based materials represent an interesting group with great potential for application. Research in biological waste management and plant amino acid supplementation seems to be an optimal direction for the future of agriculture. The chemical hydrolysis in preparing biostimulants from mealworm larvae was optimized using a response surface methodology. Through a literature review, the temperature, the mass phase ratio and the concentration of the extraction medium were selected as critical parameters in the extraction of amino acids. Due to the large number of trials needed for a single optimization, it was decided to utilize the total nitrogen content as a system response, which allowed the estimate of hydrolysis efficiency. The resulting hydrolysates in the liquid phase contained nitrogen up to 2.86% and in the solid phase 5.88%. A particular improvement in plant growth was shown in steam length (41%) and root length (31%). The proposed method of mealworm utilization is a solution to future waste management issues and is consistent with the concept of a circular economy.