Characterization of the Keratinolytic Activity of Three Streptomyces Strains and Impact of Their Co-Cultivation on This Activity

Diego Martín-González; Sergio Bordel; Fernando Santos-Beneit

doi:10.3390/microorganisms11051109

Characterization of the Keratinolytic Activity of Three Streptomyces Strains and Impact of Their Co-Cultivation on This Activity

Microorganisms. 2023 Apr 24;11(5):1109. doi: 10.3390/microorganisms11051109.

Authors

Diego Martín-González^{1

2}, Sergio Bordel^{1

2}, Fernando Santos-Beneit^{1

2

3}

Affiliations

¹ Institute of Sustainable Processes, Dr. Mergelina, s/n, 47011 Valladolid, Spain.
² Department of Chemical Engineering and Environmental Technology, School of Industrial Engineering, University of Valladolid, Dr. Mergelina, s/n, 47011 Valladolid, Spain.
³ Department of Functional Biology, Medical School, University of Oviedo, Av. Julián Clavería, 6, 33006 Oviedo, Spain.

Abstract

In this study, we describe the characterization of three efficient chicken feather-degrading Streptomyces bacteria isolated from honeybee samples and assess the impact of their co-cultivation on this activity and antistaphylococcal activity. Streptomyces griseoaurantiacus AD2 was the strain showing the highest keratinolytic activity (4000 U × mL^-1), followed by Streptomyces albidoflavus AN1 and Streptomyces drozdowiczii AD1, which both generated approximately 3000 U × mL^-1. Moreover, a consortium constituted of these three strains was able to use chicken feathers as its sole nutrient source and growth in such conditions led to a significant increase in antibiotic production. S. griseoaurantiacus AD2 was the only strain that exhibited weak antimicrobial activity against Staphylococcus aureus. UPLC analyses revealed that a significant number of peaks detected in the extracts of co-cultures of the three strains were missing in the extracts of individual cultures. In addition, the production of specialized metabolites, such as undecylprodigiosin and manumycin A, was clearly enhanced in co-culture conditions, in agreement with the results of the antimicrobial bioassays against S. aureus. Our results revealed the benefits of co-cultivation of these bacterial species in terms of metabolic wealth and antibiotic production. Our work could thus contribute to the development of novel microbial-based strategies to valorize keratin waste.

Keywords: Staphylococcus aureus; Streptomyces; antibiotic; biofertilizers; co-culture; feathers; keratinase; undecylprodigiosin.

Grants and funding

We thank the FEDER program (TCUE 2021–2023) for allowing Fernando Santos-Beneit to obtain the project with reference number: 067/229111. We also thank the European Union for supporting the work with an H2020-MSCA-IF-2016 Fellowship (UE-18-VANRESTREP-740080).