ABSTRACT
The potential to produce ethanol and xylitol from xylose by the macro basidiomycete Trametes membranacea was evaluated. All strains studied showed ethanol and xylitol production. The highest ethanol production of xylose was obtained by T. membranacea strain TM158/10 with 5.65 ± 0.21 g/L at pH 4 and 28 °C with 288 h of fermentation and 5.59 ± 0.05 g/L ethanol concentration at pH 5 and 24 °C with 360 h of fermentation. When the conversion was carried out using sugars generated from enzymatic hydrolysis of sugarcane bagasse, there were higher yields from 74 to 15% for ethanol and xylitol, respectively. Although the ethanol and xylitol production need to be optimized, this study showed for the first time the possibility of using T. membranacea for the simultaneous xylitol and ethanol production from pentose sugars, allowing for the possibility of using all released sugars during the hydrolysis of lignocelluloses.
Subject(s)
Cellulose/chemistry , Ethanol/metabolism , Saccharum/chemistry , Trametes/growth & development , Xylitol/biosynthesisABSTRACT
Polyporus dictyopus, with a large number of heterotypic synonyms, has been traditionally considered a species complex, characterized by wide morphological variation and geographic distribution. Thus, neotropical specimens previously identified as P. dictyopus from Amazonia, Cerrado and Atlantic Forest biomes were studied based on detailed macro- and micromorphological examination and phylogenetic analyses, using distinct ribosomal and protein-coding genomic regions: the nuclear ribosomal internal transcribed spacer (nrITS), nuclear ribosomal large subunit (nrLSU), and RNA polymerase II second subunit (RPB2). Two unrelated generic lineages, each one represented by different species, are reported: Atroporus is recovered and re-circumscribed to include A. diabolicus and A. rufoatratus comb. nov.; Neodictyopus gen. nov. is proposed to accommodate N. dictyopus comb. nov. and two new species, N. atlanticae and N. gugliottae. Our study showed that at least five distinct species were hidden under the name P. dictyopus. Detailed descriptions, pictures, illustrations, and a key are provided for Atroporus and Neodictyopus species.
