The effects of pre-treatment of samples on results from (1,3)--D-glucans analysis

(1,3)--D-glucans are polysaccharides from biological origin that may become airborne particles during normal working operations with contaminated materials. Exposure to airborne (1,3)--D-glucans are assumed to induce work related respiratory symptoms. The aim of the study was to investigate how the pre-treatment of samples could affect the results from -D-glucans analysis. The experiments were carried out at laboratory scale with simple models such as microbial cultures and solutions from pure glucans; bioaerosol samples were also collected in real exposure conditions. Simple models were yeast cultures (Saccharomyces cerevisiae), fungal cultures (Penicillium brevicompactum) and aqueous solutions (1000 pg/ml) of pure (1,3)--D-glucan from Barley, of Laminaran and of Schizophyllan. Microbial cultures, pure glucans solutions were treated submitted to different treatments including shredding with glass beads, autoclaving, treatment with a NaOH 0.3 N solution, treatment with a 0.1 % Tween 80 solution, sonication and not treated. Similar treatments were applied on bioaerosol samples to taken from household waste recycling centre. (1,3)--D-glucans were analyzed with the Glucatell® kit. Results were expressed in pg/ml ou en pg/m3. Results showed a significant effect (p<0.0001) of treatments on (1,3)--D-glucans concentrations. For microbial cultures, shredding with glass beads led to the highest concentrations. Results from pure (1,3)--D-glucan solutions were more contrasted. The highest concentrations were monitored after treatment with a 0.1 % Tween 80 solution led to for (1,3)--D-glucan from Barley and Laminaran and after autoclaving for Schizophyllan. Results from bioaerosol samples are also presented. Treatments are assumed to act on both the solubility of glucans and their release from cell envelops. The study suggests a standardization of pre-treatment protocols for measurement of (1,3)--D-glucanes in bioaerosol samples