RESUMO
New substrates, 2-(2'-benzothiazolyl)-phenyl (BTP) cellooligosaccharides with degree of polymerization (d.p.) 2-4 (BTPG(2-4)) were synthesized for the screening of microbial cellulolytic activity in plate assays. The substrates were very efficient that was shown for several cellulolytic bacteria, including yeast-like isolates from Kamchatka hot springs. Three tested bacterial strains and eighteen of 30 of the yeast isolates showed ability to degrade cellulose with cellobiohydrolase, beta-glucosidase and endo-cellulase activities measured with standard substrates. The structures of 2-(2'-benzothiazolyl)-phenyl oligosaccharides were solved by NMR- and mass-spectrometry. The usefulness of the 2-(2'-benzothiazolyl)-phenyl substrates were also shown during purification of the B. polymyxa cellulolytic complex, which consists of at least three types of the enzymes: cellobiohydrolase, endo-beta-d-glucanase and beta-glucosidase.