A laboratory model for studying environmently dependent chemical modifications in textile cellulose

We have developed a laboratory model to evaluate possible microbial impact on cellulose during long-term contact with air microorganisms. This model is based on the capillary zone electrophoretic/mass spectrometric estimation of modified glucose residues in cellulose enzymatic hydrolysates isolated from linen samples. We subjected these samples to a pump-directed air flow line for 8 days and 10 weeks. Simultaneously, we measured protein contamination of the samples followed by AMS-determination of the associated C-14 and C-13 values. All measurements were done in non-aseptic environments in two different geographical/ecological regions. We pre-impregnated all experimental samples with deionized water and pretreated the control samples with urea and sodium azide in order to prevent both enzymatic activity and microbial growth. Our results show that the filtration of atmospheric air through the linen samples leads to a statistically significant methylation and acetylation of textile cellulose, depending on air volume (and therefore the amount of air bacteria cells), ecological conditions, and the presence of bacteriostatic (sodium azide) and protein denaturing (urea) agents. We found that the amount of alkylation in the cellulose samples correlates with the measured C-14 and C-13 values and protein contamination levels. A biochemical mechanism of the phenomenon and its possible application for forensic and archaeological chemistry are under discussion.