Evaluation of the Disposition Of Swine Hair Pre-treated with Trichoderma sp. in the Soil

The growing animal protein production results in a high generation of waste considered environmental pollutants, such as swine hair, which is composed of keratin. This protein has characteristics such as rigidity, making it a natural polymer. Given this, alternatives for this waste to be disposed of without harming the environment are desirable, such as biological pre-treatment that makes the waste less rigid, facilitating access to nutrients present in its structure when disposed of in the soil and also enabling the production of keratinase, one an enzyme with high specificity for residues composed of keratin. In this context, this study aimed to evaluate the final disposition of swine hair pre-treated with Trichoderma sp. in the soil and its effect on the development of tomato seedlings and to evaluate the production of keratinase from the pre-treatment process. As a result, the final disposal of these pre-treated residues was effective since there were no significant changes in soil characteristics but increased nutrients such as nitrogen, potassium, and calcium in tomato seedlings. Also, keratinolytic activity values of 326.61 ± 42.33 and 403.3 ± 71.65 U/g were obtained within 24 h of the process. Finally, it can be concluded that in addition to not negatively affecting the environment and the development of tomato seedlings, after biologically pre-treated, swine hair can act as an adsorbent of heavy metals, reducing their concentrations in the soil. So, the significance of this study could be synthesized in biological pre-treatment enabled the use of swine hair for multivariate purposes; the fermentation process resulted in elevated keratinolytic activity; the treated swine hair decreased concentrations of heavy metals in the soil; and swine hair pre-treated biologically provide the increment of nutrients in the soil. Graphical Abstract