Atividade celulolítica de fungos isolados de bagaço de cana-de-açúcar e madeira em decomposição

Abstract

Resumo -O objetivo deste trabalho foi identificar isolados de fungos a partir de bagaço de cana-de-açúcar e madeira em decomposição e avaliar a sua atividade celulolítica em bagaço de cana. Cinco isolados foram avaliados, tendo-se como referências os fungos Trichoderma reesei QM9414 e T. reesei RUT C30. A atividade celulolítica foi estimada pela capacidade hidrolítica do extrato enzimático dos fungos cultivados em bagaço de cana sobre os substratos papel de filtro (atividade celulolítica total) e carboximetilcelulose sódica (atividade da endoglucanase). Os isolados foram identificados pela análise molecular da região 26S rDNA. Os gêneros Paecilomyces, Aspergillus, Acremonium/Penicillium e Trichoderma foram identificados. Embora T. reesei QM9414 tenha apresentado a mais alta atividade celulolítica total, alguns isolados também apresentaram alta atividade de endoglucanase. A biodiversidade, em nichos como bagaço de cana-de-açúcar, pode fornecer linhagens de fungos celulolíticos com grande potencial biotecnológico.Termos para indexação: Acremonium, Aspergillus, Paecilomyces, Penicillium, Trichoderma, celulase, endoglucanase. Cellulolytic activitity of isolated fungi from sugarcane bagasse and decayed woodAbstract -The objective of this work was to identify fungi isolates from sugarcane bagasse and decayed wood, and to evaluate their cellulolytic activity on sugarcane bagasse. Five isolates were evaluated, as compared to Trichoderma reesei QM9414 and T. reesei RUT C30. The cellulolytic activity was estimated through the hydrolytic capacity of the enzymatic extract of fungi grown on sugarcane bagasse over filter paper (total cellulolytic activity) and sodium carboxymethyl cellulose (endoglucanase activity). The isolates were identified by molecular analysis of 26S rDNA region. Paecilomyces, Aspergillus, Acremonium/Penicillium and Trichoderma genera were identified. Although T. reesei QM9414 showed the highest total cellulolytic activity, some isolates showed higher endoglucanase activities. Biodiversity found in habitats such as sugarcane bagasse can provide strains of cellulolytic fungi with great biotechnological potential.

Fungi isolated from Miscanthus and sugarcane: biomass conversion, fungal enzymes, and hydrolysis of plant cell wall polymers

“…However, the 24% correlation between biomass loss and the four enzyme activities combined with the observation that the two best fungi for bioconversion of Miscanthus , P. chrysosporium and Chloridium sp1 , never reached the maximum activity for any enzyme, supports the argument that most or all of the fungi studied here must harbor uncharacterized enzymes that are important to bioconversion [4]. This same conclusion has been reached by others who observed an increase in the bioconversion ability of commercial T. reesei enzyme preparations upon the addition of secreted proteins from a variety of fungi [11,12,24]. …”

“…Prior efforts by others at bioprospecting for mesophilic fungi have discovered five fungi isolated from sugarcane bagasse and wood with endoglucanase activities that compared favorably to enzymes from T. reesei [11], and 19 fungi selected from 74 species, cultivated from temperate French forests and tropical French Guiana forests, whose secretomes increase biomass conversion of maize bran when added to commercial T. reesei enzyme cocktails [12]. Plant pathogenic fungi have also been studied with the finding that many of these fungi bioconvert as well or better than T. reesei (for example, on xylans, species of Mucor , Rhizoctonia , and Cylindrocarpon were superior to T. reesei ), and that fungi that parasitize monocots bioconvert these plants more effectively than fungi parasitizing dicots, and vice versa [13].…”

Cellulase Production by Endophytic Strains of <i>Trichoderma reesei</i> from <i>Baccharis dracunculifolia</i> D. C. (Asteraceae)

“…Basso, Gallo and Basso [13] (2010), when evaluating the cellulolytic activity of T. reesei strains, isolated from sugarcane bagasse and decaying wood, observed values of 12.58 IU/g of unsupplemented substrate at 28˚C in 35 days. Once more, the data are similar to those observed in this work, but considering the behavior in unsupplemented medium, the values obtained in this study are lower, reaching 7.93 IU/g in 29 days.…”

Efeito da estratificação em substrato esterilizado na qualidade sanitária de sementes de <i>Ilex paraguariensis</i>

“…em flores, frutos e sementes despolpadas por viveiristas, assim como em sementes estratificadas de erva-mate. Este gênero é considerado saprofítico e apresenta capacidade de produção de enzimas celulolíticas (BASSO;GALLO;BASSO, 2010;LOPES et al, 2016), fazendo com que este fungo possa atuar no processo de degradação do endocarpo e do tegumento das sementes de erva-mate, auxiliando no processo de superação de dormência. Esse fungo também foi relatado em sementes de dendê (CYSNE; SOUZA; LIMA, 2015), Myracrodruon urundeuva (BARBOSA et al, 2014) e Amburana cearenses (PINHEIRO et al, 2014).…”