DETERMINATION OF CHITIN IN FUNGI AND MYCORRHIZAL ROOTS BY AN IMPROVEDHPLC ANALYSIS OF GLUCOSAMINE

A method to measure chitin content in fungi and ectomycorrhizal roots with high-performance liquid chromatography (HPLC) was developed. Meas urements of fluorescence of 9-fluorenylmethylchloroformate (FMOC-Cl) d erivatives of glucosamine were made on acid hydrolysates of pure chiti n, chitin-root mixtures and fungal-root mixtures. The method was appli ed on 5 isolates of ectomycorrhizal fungi, and ectomycorrhizal and non -mycorrhizal Finns sylvestris roots. Interference from amino acids was removed by pre-treatment of samples with 0.2 N NaOH. This pre-treatme nt did not reduce the recovery of chitin, nor did plant material affec t the recovery of chitin. The HPLC method was compared with a colorime tric chitin-method by measurements on root-fungal mixtures, with known fungal content. The HPLC method gave estimates of fungal biomass whic h were equal to the expected while the colorimetric method showed valu es significantly (p<0.001) lower than the expected. The present chitin method offers a sensitive and specific tool for the quantification of chitin in fungi and in ectomycorrhizal roots.