SELECTION AND CULTIVATION OF CELLULOSE-DEGRADING AND LIGNIN-DEGRADINGFUNGI

Wood-degrading fungi isolated from different sources, and cultures fro m collections of the Institute of Microbiology and Institute of Botany , Uzbekistan Academy of Sciences,, were screened. Among the 34 selecte d cultures possessing cellulose-degrading capability, 15 were capable of oxidizing tannin and gallic acid, which is characteristic of lignin olytic cultures. The following active cultures of basidiomycetes were selected: Panus tigrinus (Bull. ex. Fr.) Sing. UzBI-013, Pleurotus ost reatus (Jacg. ex. Fr.) Kumm. UzBI-H105, Fomes fomentarius (L. ex. Fr.) Kickx. Fr. UzBI-155, and Inonotus hispidus (Pers.) UzBI-T8. They acti vely utilized hemp-mallow shaft lignin (HMSL) as the sole source of ca rbon in the medium. It was established that cellulolytic, xylanolytic, and ligninolytic enzymes were produced during growth of the cultures on ligninocellulose wastes (depleted bagasse of cotton seed ground oil cake, rice hull, and hemp-mallow shaft). Along with cellobiase, endogl ucanase, and xylanase activity, P. ostreatus and P. tigrinus fungi wer e capable of secreting the enzymes peroxidase and laccase, unlike F. f omentarius and I. hispidus, which did not secrete laccase. The chemica l composition of ligninocellulose wastes was studied before and after cultivation of the fungi. During 30-day growth and development of the fungi, 23-78% of cellulose was utilized, 21-80.4% of hemicellulose, an d 21-58% of lignin. Degradation of biopolymers was highest during 10 d ays of fungal cultivation. It was shown that the production of those e nzymes responsible for biopolymer degradation depended on the composit ion of the ligninocellulose components of the medium.