# Design of Fermentative Technology for the Valorization of Pig Bristle Keratins into Biostimulant for Agricultural Applications

## TL;DR

This paper presents a fermentation method to convert pig bristle waste into a biostimulant that benefits agriculture and the environment.

## Contribution

A novel fermentation technology using Sporosarcina luteola to valorize pig bristle keratins into a biostimulant is developed.

## Key findings

- The biostimulant includes S. luteola biomass, enzymatic secretions, and hydrolyzed organic matter from pig bristles.
- The product showed positive effects on soil enzymatic activities and plant performance under oxidative stress.
- The process offers agronomic and environmental benefits by repurposing keratin-rich waste.

## Abstract

The elimination of keratin-derived waste, such as pig
bristles,
represents a significant challenge due to its high production levels
and resistance to degradation. However, the keratinous composition
also makes pig bristles a valuable waste material with significant
potential for bioconversion into biostimulants rich in bioavailable
nitrogen, peptides, and amino acids. To achieve degradation, microorganisms
with keratinolytic activity isolated from the raw material were selected.
Based on the best performance in plant PGP traits, solubility, and
protease activity, Sporosarcina luteola was chosen to implement a fermentation technology that converts
pig bristle waste. The fermented product comprises three classes of
biostimulant components: the biomass of S. luteola, the enzymatic secretions of this microorganism, and the hydrolyzed
organic matter from pig bristles, which is rich in protein hydrolysates
and free amino acids. The biostimulant was evaluated in soil at the
biochemical level (enzymatic activities) and in plants under oxidative
stress, demonstrating a positive effect. These findings highlight
the fermentation process using S. luteola as a promising strategy for the comprehensive valorization of pig
bristle waste, resulting in products with significant agronomic and
environmental benefits.