Arthroderma tuberculatum and Arthroderma multifidum Isolated from Soils in Rook (Corvus frugilegus) Colonies as Producers of Keratinolytic Enzymes and Mineral Forms of N and S.

Justyna Bohacz,Ignacy Kitowski,Michał Możejko

doi:10.3390/ijerph17249162

Abstract

Keratinolytic fungi representing the genus Arthroderma that were isolated from the soils of a rook (Corvus frugilegus) colony were used as biological agents for the disposal of waste feathers. The aim of this study was to assess the abilities of Arthroderma tuberculatum and Arthroderma multifidum fungi with a varied inflow of keratin matter to biodegrade waste feathers. The evaluation was based on the determination of feather mass loss, the activity of keratinolytic enzymes, and the content of mineral N and S forms. It was found that the activity of protease released by the fungi contributed to an increase in the level of soluble proteins and peptides and the concentration of ammonium ions, as well as alkalization of the culture medium. Keratinase activity was significantly correlated with sulfate release, especially in A. tuberculatum cultures. The strains of A. tuberculatum fungi isolated from the soil with the highest supply of organic matter, i.e., strains III, IV, and V, had the lowest enzymatic activity, compared to the A. multifidum strains, but they released mineral nitrogen and sulfur forms that are highly important for fertilization, as well as nutritionally important peptides and amino acids. A. tuberculatum strains can be used for the management of waste feathers that can be applied in agricultural practice.

Highlights

As reported by Mokrejs et al [1], between 0.9 and 1.5 billion kilograms of waste feathers are produced annually in the poultry processing industry in the USA
Similar to other keratin waste, chicken feathers contain keratin, i.e., a protein that is characterized by high mechanical strength and resistance to physicochemical factors and the enzymatic lysis associated with the presence of numerous disulfide bridges [5]
The aim of this study was to evaluate the keratinolytic abilities of fungi isolated from soil that was characterized by a constant inflow of keratin matter, i.e., located below nests of the rook Corvus frugilegus

Summary

Introduction

As reported by Mokrejs et al [1], between 0.9 and 1.5 billion kilograms of waste feathers are produced annually in the poultry processing industry in the USA. Korniłłowicz-Kowalska and Bohacz [2] and Staroń et al [3] have reported that the level of the generation of this waste in Poland ranges from approximately 77,000 to 90,000 tons. This value reaches 2 million tons per year, as shown by Verma et al [4]. Similar to other keratin waste (hair, bristle, horns, hooves, etc.), chicken feathers contain keratin, i.e., a protein that is characterized by high mechanical strength and resistance to physicochemical factors and the enzymatic lysis associated with the presence of numerous disulfide bridges [5]. Chicken feathers serve as an enhancer in the production of

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