Protein recovery from wastewater animal processing by-products of rendering plants for biostimulant applications in agriculture

This paper presents the results obtained from the recovery of valuable proteins contained in category 3 wastewater from a rendering plant of poultry animal by-products (ABPs) using enzymatic hydrolysis as a bioprocess for its recovery. The different parameters of the bioprocess (i.e., type of enzyme, load of enzyme and hydrolysis time) have been optimised to obtain a recovery of protein between 87% and 97%, with 60% of total amino acids in the hydrolysed product and free amino acid content in solution higher than 5%, suitable for improving plant growth by germination. Finally, the dosage of the prepared biostimulants has been validated to enhance by 17% the germination of Chinese cabbage and by 20% that of lettuce seeds. As a result, the applicability of this protein for agriculture will be improved and wastewater management costs for industries will be reduced.