GROWING BASIDIOMYCETES IN BIOREACTORS TO BE APPLIED TO BIOREMEDIATION OF HCB IN SOIL

摘要

Psilocybe castanella CCB444 and Lentinus sp. CCB274 were selected from among 36 basidiomycetes strains from Brazil, because they were able to deplete hexachlorobenzene (HCB) in soil. The fungal development was evaluated into 400kgbioreactor with HCB free and sterilized soil. The incubation conditions were those that promoted the best HCB mineralization rate in laboratory, with the no-sterilized air injection. The following parameters were assessed: temperature, pH, total organic carbon and moisture content of soil. The basidiomycetes growth were evaluated by estereoscopic analysis, biomass and ligninolitic enzymes activity. A survey of autoctone microbial was made by using pour plate method in nutrient-agar and Martin media, with counting of colonies forming units (CFU). The design of bioreactors showed suitable to maintain great conditions to basidiomycetes growth. In the Lentinus sp bioreactor ocurred biomass increase until 36 days of incubation. It was detected ABTS-oxidizing enzymes, with activity peaks at 7 and 36 days. The organic carbon do not varyed significantly and the autoctone microbial population stayed small. P. castanella biomass reduced in the first days of incubation, stabilizing by 14 th day, but it was detected enzymes peaks at 7 days of incubation. The counted microorganisms stayed low too, with a little increase of filamentous fungi at 73 days. The technique used for basidiomycetes recovery showed satisfactory and the colonization of micelium in soil was confirmed by estereoscopic photographs. The pH has reduced during the period of incubation, stabilizing in 3.8, in both of bioreactors. The evaluation of HCB degradation in bioreactors will begin in this year.