Нижневолжский археологический вестник (Dec 2018)
The Identification of Wool by the Number of Keratinolytic Microorganisms in the Ground of Ancient and Medieval Burials
Abstract
The paper describes the method for determining the initial presence of wool products in the burial rite of several cultures of the Bronze Age and the Middle Ages. The method is based on the analysis of the number of keratinolytic fungi in soils. Keratin is a proteinaceous biopolymer, which is a part of wool, leather, feather, and other materials. Its decomposition in soil occurs with the participation of a small group of soil fungi with keratinolytic activity. The ingress of wool and other keratin-containing substrates in the soil of archaeological monuments in antiquity provoked the sharp increase in the number of keratinolytic fungi. After the entire keratin-containing substrate was utilized, these fungi became dormant forms (cysts and spores), and in this state they could persist up to nowadays. The presence of keratinolytic microorganisms has been determined using the plate method – by direct counting of colony-forming units in media with wool brought into the substrate as the sole source of nutrients for soil microorganisms. The experiments’ object is represented with the samples of ashes of beddings, the cover over the burials, the under-skeleton soil from burials of the Bronze Age, as well as the soils from medieval burials with cremations. The analysis of under-skeleton soil of the Bronze Age burials shows that the samples taken under the knees and under the feet were characterized by a high content of keratinolytic fungi, which may indicate the initial presence of the shoes made of wool or leather. A high number of keratinolytic fungi in some burials has been revealed at a considerable distance from the skeleton, which indicates the presence of items made of wool in the decoration of the burial bed. In medieval cremation burials, traces of leather or woolen containers with cremated remains have been found.
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